Office of Operations
21st Century Operations Using 21st Century Technologies

Effects on Intelligent Transportation Systems Planning and Deployment in a Connected Vehicle Environment

Chapter 3. Connected Vehicle Impacts on Core Intelligent Transportation System Functions

This chapter discusses potential Connected Vehicle (CV) impacts on core Intelligent Transportation Systems (ITS) functions. For each ITS category considered, the research discusses:

  • Current Services and Trends—Summarizes the current state of the practice and the results of the literature search.
  • CV Technology Opportunities—Identifies ways CV technology may be incorporated into ITS and operations.
  • Impacts on ITS Planning and Deployment—Identifies the potential impacts of CV technology on ITS planning and deployment.
  • Impacts on Data—Identifies the potential impacts of CV technology on data.
  • Impacts on Operations—Identifies the potential impacts of CV technology on data.
  • Roles and Responsibilities—Identifies key roles and responsibilities.
  • Challenges and Uncertainties—Lists issues that need to be resolved and issues that may influence the implementation of CV technology.

Following the discussion of the topics identified above, a relevant case study on agency examples in incorporating connected vehicle technology into ITS planning, programming, deployment and operations is presented.

Traveler Information

Traveler information systems refer to strategies designed to inform transportation users of various aspects important for their trip. Traveler information services have evolved from television and radio reports (which are still heavily used) to public sources such as 511 to numerous smartphone and telematics applications that provide not only real-time data but predictive estimates of travel times.

Current Services and Trends

With proliferating data sources that can be used in combination by ITS and operations personnel, data sharing frameworks are of great interest. The goal of these is to provide a structure for enhancing data transferability while addressing security concerns. In general, there is a pervasive sentiment that traveler information can improve mobility as data accessibility increases. There seems to be a growing acceptance of private information sources, as these sources of information could offer mobility information at a greater level of detail than public ones. Furthermore, as accessibility to data increases, research has been able to focus on specific transportation issues, such as ridesharing services, or location specific traveler information. However, research continues to highlight the importance of security and data privacy, the need for which has been tackled in a variety of different ways in pilot projects.

Connected Vehicle Technology Opportunities

Vehicle-based data may potentially offer more specific and detailed information. CV technology may be able to provide a wealth of detailed data to support traveler information services including vehicle speeds, weather-related roadway condition information (wet or icy pavement) and even information on crashes. Until a larger portion of the fleet is outfitted with the technology other means of collecting traffic volume data will be needed. It is also unclear whether data generated from vehicles would be made available for traveler information purposes.

Tailored information could be provided directly to the vehicle. In-vehicle telematics offer the potential to provide tailored messages to individual vehicles or groups of vehicles based on their speed and location. Some of this is currently done through smartphone apps but could be enhanced with CV related data. For example, very detailed data on icy spots could be broadcast to individual vehicles approaching that location.

Site-specific warning signs such as those on curves or in school zones may be supplemented by virtual or targeted data. Warnings could be sent to specific vehicles that are approaching these zones at too fast a speed. General warning signs could potentially be removed if CV technology reaches full deployment.

Impacts on Intelligent Transportation Systems Planning and Deployment

Traveler information has been increasingly migrating to the private sector in recent years and likely will continue to do so. The ability to access vehicle data for traveler information purposes remains unclear. However, it is likely that there will be a market for data from both private and public sources. Private parties, which already collect data from navigation devices and smartphones and process it for use by consumers, will continue to refine and enhance products. Agency understanding of and partnership with private sector providers will become increasingly important as part of this shift. CV-related data and products are likely to expand their current role as a source of information for companies and organizations in the market for data and traveler information.

Information delivery is evolving as more in-vehicle communications are harnessed as the delivery source to travelers. Sources such as Dynamic Message Signs (DMS), Highway Advisory Radio (HAR) and 511 are less needed and are likely to become obsolete in the short- and mid-term as private sources take over and are able to provide more detailed, targeted information. Even for emergency situations, agencies may find it more efficient to use private sources rather than to support legacy systems.

The use of CV technology to deliver messages directly into the vehicle will provide the opportunity to tailor messages more directly based on vehicle location and possibly speed, and eventually allow the phasing out of current information services such as 511 and DMS. Fixed asset DMSs may ultimately be replaced, but more slowly, as in-vehicle penetration of CVs needs to grow to a higher level before DMS can be fully removed. If shorter lives are anticipated for certain fixed assets, rather than invest in full DMS replacements, agencies may look at less expensive options; for example roadside or portable signs.

Public agency goals on topics like social equity will likely not perfectly align with private sector operations. Agencies will need to work to ensure traveler information is reaching as many transportation system users as possible, not merely those with the newest technology available.

Impacts on Data

It is anticipated that agencies will continue to collect data but become less involved in providing information. CV-related data will be useful to public agencies in areas such as system management and collection of system condition data. However, dissemination of information is likely to migrate to targeted in-vehicle systems, and private sector sources are likely to grow. Use of in-vehicle systems and probe data will likely mean a larger role for the private sector, and the need to develop partnerships that serve the needs of all parties.

Agencies will need to ensure the security and privacy of data. Current pilot projects have dealt with this in a variety of ways, but generally find it to be a challenge.

Impacts on Operations

As CV technology penetration grows, agencies will find greater opportunities for more complex and tailored traveler information applications. Agencies will have the opportunity to expand their service offerings but will need to develop new standards and guidance on how and when to employ traveler information functions and how to facilitate capacity development and experimentation without endangering the public or investing in inefficient outcomes.

Agencies can potentially increase active traffic management with better real-time speed data and more opportunity to engage and reroute traffic.

Roles and Responsibilities

Public sector agencies have a major role in setting a course for traveler information, managing traveler information applications, setting guidance and standards, and ensuring equity. They would likely benefit from working with private sector partners in developing and sharing data and gaining access to distribution networks.

Challenges and Uncertainties

The timing of CV and Automated Vehicle (AV) market penetration is uncertain. Agencies will need to closely track private sector developments in order to make sound decisions regarding changes to legacy ITS traveler information systems. While it appears that systems such as 511 and HAR could potentially be phased out, DMS and systems related to emergencies and hazardous conditions must be more carefully considered.

Ownership and use of CV-related data is an issue that will impact traveler information services. This is an area where agencies and private vendors of traveler information will likely want to work together to make sure that this information is available to serve the public while protecting the privacy of individual drivers.

Case Study on Virtual Dynamic Message Signs

DMS, also known as variable message signs, are installed on highways so that the traffic management center can provide current information to the traveling public about matters such as crashes, detours, and weather warnings. These traditional DMS systems are expensive to deploy and require ongoing maintenance. Aside from the sign itself, agencies also need to invest in supporting structures and communications. Although DMSs provide valuable information to the traveling public, limitations such as legibility distance and language barriers can cause comprehension issues and excessive braking. (Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 30.)

The Mid-Atlantic Universities Transportation Center (MAUTC) has studied the potential benefits and costs to utilize CV technology to provide a virtual DMS system. (Quantifying Cost Savings of Connected Vehicle-Enabled Applications: Virtual Dynamic Message Sign System Case Study.) They found that CV technology could provide a more cost effective and flexible solution through virtual DMS. The messages may be received through an in-vehicle system using CV communications. Messages could be made audible and/or converted to a different language.

To illustrate the costs of deploying a virtual DMS project in comparison to a traditional DMS project, an average traditional DMS project and a hypothetical virtual DMS project were envisioned in order to itemize the costs. For these example projects, capital costs of traditional and virtual DMS systems are compared at a high level. The traditional DMS system project consists of two DMSs for each side of the freeway, related supporting structures and controllers, and a half-mile of fiber-optic communication. The virtual DMS project consists of two Road Side Units (RSU) for each side of the freeway and backhaul communications for each site.

Table 1 lists and compares the capital costs of a traditional infrastructure-based and CV-based, virtual DMS system. The total average cost of the traditional DMS system is approximately $560,000 and total high-end cost of the CV-based virtual DMS system is approximately $122,000. As this hypothetical example shows, the CV-based system can potentially cost much less because of the lower asset requirements and labor costs. For example, while a traditional DMS needs to be mounted across the highway so that it is in line of sight for drivers, an RSU can be installed along the road since messages are received inside the vehicle. In addition to being less expensive, the RSU may be a more versatile investment, as it can be utilized for other in-vehicle messages such as work zone and queue warnings, as well as for data collection.

Table 1. Preliminary capital cost comparison of traditional and virtual dynamic message signs.
Traditional DMS Item
(An Evaluation on the Economic Feasibility
and Implementation of Virtual Dynamic
Message Signs
Presentation, slide 12.
Traditional DMS Total Average Cost
(An Evaluation on the Economic Feasibility
and Implementation of Virtual Dynamic
Message Signs
Presentation, slide 12.
CV-Based Virtual DMS Item CV-Based Virtual DMS Total Maximum Cost
(Preliminary estimates have large ranges.
The maximum value is presented here.)
DMS (2) $217,000 RSU (2) $42,400
Support Structures (2) $231,400
Communications and Power (0.5 mile) $67,500 Backhaul Communications (2) $80,000
Controller and Other (2) $43,800
Total $559,700 Total $122,400

(Source: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 30.)

In order to receive and display messages from the RSU, the traveling public would need to be in compatible CV-equipped vehicles. In the short term, the traveling public would be responsible for investing in an aftermarket On Board Unit (OBU) (similar to toll transponders). Given that current DMS systems provide information to the public at no cost, it would be difficult to motivate voluntary investment if this were the only benefit. Agencies may consider providing incentives or offering to install aftermarket units in order to pilot the virtual DMS system and introduce it to the traveling public.

As market penetration of CV-enabled passenger vehicles matures, and as traditional DMSs reach the end of life, agencies may consider investment and transition to a CV-based virtual DMS. During the transition to market maturity, agencies may need to operate in a mixed environment with both traditional and virtual DMS systems.

Freeway Management

Freeway management includes systems and services designed to optimize traffic flow and safety on limited access roadways. Related ITS resources include Closed Circuit Television (CCTV) cameras, vehicle detection systems, ramp meters, service patrols and traffic management staff and software.

Current Services and Trends

Current research is focused on how CV can improve information dissemination; from investigating how roadside equipment can evolve to incorporate CV to experimenting with new innovative ways to disseminate freeway information to users, like smartphone applications and on-board equipment. Research is also currently focusing on ways to enhance data collection and freeway surveillance using CV technology, ultimately improving traffic operation strategies, like more efficient speed harmonization strategies and dynamic lane management.

Connected Vehicle Technology Opportunities

An important opportunity presented by CV technology is that it may allow agencies to have enhanced data on traffic conditions on freeways with a potential lower cost than with current strategies.

CV technology could advance the shift from reactive to proactive traffic management. Having reliable real-time data could enable traffic agencies to consider new operational strategies, shifting from fixed reactive strategies, to more dynamic operations that incorporate the unique conditions of each event.

Data from CV has the potential to improve freeway operations significantly, at a low cost. This premise will likely depend on many factors, like CV penetration rates, data ownership, management, and integration. Best-practices will likely define data management frameworks as research continues to develop in this area.

CV technology offers an opportunity to reduce freeway impacts of traffic incidents. With a more efficient Traffic Information Dissemination system, agencies would be able to alert users of traffic condition changes with greater precision and timelier information, ultimately reducing congestion on freeways due to traffic incidents.

The CV technology used for freeway management may also evolve to support asset management activities. Pavement and some bridge condition information could potentially be collected from the vehicle.

Impacts on Intelligent Transportation Systems Planning and Deployment

Over time, the combination of CV and AV technologies is expected to reduce freeway crashes significantly. This would free up resources currently used for incident management to support other needs, such as the communications and security infrastructure needed to support these systems. These changes would in turn impact the mix of personnel requirements for ITS and operations agencies.

A relatively small market penetration of CV technology may allow agencies to reduce costs currently incurred in specialized data collection activities for asset management.

Impacts on Data

CV market penetration may lead to better real-time data resources and more opportunity for benefits from active management of freeway corridors, even those without heavy ITS instrumentation. As with other ITS functions discussed, there would need to be a mechanism in place for the collection, analysis, and storage of new CV data streams. This mechanism should allow for partnership and coordination with the private sector to optimize efficiency.

Impacts on Operations

As noted earlier, CV technology could potentially advance the shift from reactive to proactive traffic management. Having reliable real-time data could enable traffic agencies to consider new operational strategies, shifting from fixed reactive strategies, to more dynamic operations that incorporate the unique conditions of each event.

Roles and Responsibilities

Public sector agencies have led—and will likely continue leading—investment in freeway management infrastructure and applications, as well as the establishment of standards and goals for the utilization of this infrastructure. As CV technology advances, public agencies would likely benefit from working more with private sector partners in developing and sharing data and gaining access to distribution networks.

Challenges and Uncertainties

To incorporate CV technology, traffic management agencies will likely need to upgrade current data management and security systems, seeking to incorporate data from CV technology. This may result in significant investments in infrastructure (like larger data servers and roadside equipment), and personnel training (accounting for analysis of large quantities of data and more dynamic freeway operation strategies).

As vehicular technology evolves, there is uncertainty on the effect it will have on traffic safety. Although CV technology has the potential to improve safety, there are still many questions on how information can be disseminated to drivers without increasing distraction. Furthermore, there are still questions regarding the impact of CV technology on the current fleet of vehicles, specifically about whether aftermarket products can be safely incorporated into currently non-equipped vehicles.

Case Study on Curve Speed Warning Systems

CV technology promises the opportunity to reduce physical infrastructure and to communicate and tailor safety warnings to individual vehicles or groups of vehicles.

Current Curve Speed Warning (CSW) systems use DMS and radar that display warnings to drivers when their travel speeds exceed safety thresholds. CV technology can potentially integrate data from the infrastructure (e.g., slippery road surface condition) and vehicle to deliver more accurate and robust warnings to drivers through an in-vehicle display. U.S. DOT has released a Concept of Operations on CSW (and other V2I safety applications) describing the user needs, benefits, and operational scenario in detail.

California Partners for Advanced Transit and Highways (PATH) have conducted preliminary tests on a prototype CSW application. Results showed that the system was able to integrate vehicle sensor, digital map, and Global Positioning System (GPS) information and provide appropriate warnings when speeds were too high. (VII California: Development and Deployment Proof of Concept and GroupEnabled Mobility and Safety (GEMS))

To illustrate the costs of deploying a C/AV CSW pilot system, table 2 presents a high-level estimate of the capital costs to deploy smartphone infrastructure, equipment, and CV CSW in a hypothetical CSW pilot project. In this hypothetical project, RSUs would be installed along 10 curves with high crash rates and aftermarket OBUs would be installed on 30 agency vehicles. The total cost of the project would be an estimated $461,000 to $1.1 million.

Table 2. Preliminary cost estimates for connected vehicle curve speed warning.
Item Quantity Per Unit Cost Total Costs
RSU 10 curves $13,100-$21,200 $131,000-$212,000
Backhaul Communications 10 curves $3,000-$40,000 $30,000-$400,000
Light Vehicle Aftermarket OBU 30 vehicles $1,000-$10,000 $300,000
smartphone Project Total empty cell empty cell $461,000-$1,073,000

(Source: Adapted from: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 44.)

When piloting the CV CSW application, the project timeframe should ideally be long enough to allow an adequate sample of data to be collected and analyzed. Then the CV CSW data could be compared with conventional CSW data to gauge its ability to provide accurate information in a timely manner and motivate speed compliance.

In the short term, CV may supplement current static and radar-based signs. In the medium to long term, as CV technology reaches higher market penetration, the traveling public may receive in-vehicle warnings, which has the long-range potential of making physical signs obsolete. Infrastructure deployed during this transition should continue to support the safety needs of unequipped vehicles. Furthermore, as AV technology improves over the medium to long term, fully automated vehicles may utilize both on-board sensors and CV technology to adjust the vehicle speed accordingly.

Arterial Management

Arterial management strategies are designed to improve traffic flow and safety along arterial roadways. They are focused heavily on improving the efficiency of traffic signal operations but may also include ITS elements common to freeway management.

Current Services and Trends

Researchers are investigating the best approach to incorporate CV technology into arterial management strategies, seeking to improve mobility systemwide with the use of data from CV. It is expected that arterial management could be enhanced by having more dynamic control strategies, at a potentially lower cost. Specifically, FHWA's CV pilot program is testing the communications between CV-equipped vehicle and signal controllers to determine how dissemination of Signal Phase and Timing (SPaT) information can enhance arterial flow and safety. Furthermore, as with freeway management, researchers are evaluating possibilities to enhance current network surveillance and regional traffic management systems, looking at strategies that would reduce congestion and its environmental externalities across the network, moving from corridor analysis to systemwide solutions.

CV Technology Opportunities

One of the most important opportunities presented by CV technology is to communicate with infrastructure to provide more efficient network mobility. Transmitting SPaT information (and MAP or intersection geometric information) to the vehicles can enable them to reduce the number of stops. Feeding vehicle information back to dynamic control systems can potentially mitigate both congestion and its environmental impacts.

CV technology presents an opportunity to improve safety-related strategies. CV technology can be used to warn drivers if their trajectory is likely to result in a traffic signal violation, and could extend the green if a potential violation is imminent, thereby reducing the risk of a conflict. It could also be used to provide in-vehicle warnings regarding approaching emergency vehicles including their location and direction.

Better and more reliable network operation data may be available through CV data. As for freeway management systems, CV technology could allow agencies to have reliable data to characterize traffic conditions that cause non-recurring congestion on arterial networks, including identification of weather conditions and temporary lane blockages.

CV technology presents an opportunity to improve safety for non-motorized users. There has been significant work in the development of CV technology that can be incorporated into smartphones. This would allow pedestrians and cyclists to communicate their location and movement to vehicles, providing advanced warning of their presence. Warnings could be sent back from the vehicles to non-motorized users. Safeguards could also be brought into the infrastructure; for example, controller based CV technology could detect a vehicle about to run a red light and defer the pedestrian phase of the signal.

The CV technology used for arterial management may also evolve to support asset management activities (as noted in the freeway management discussion). Pavement and some bridge condition information could potentially be collected from the vehicle and collected through roadside infrastructure.

CV technology also allows a better "picture" of the vehicles approaching the intersection including queue locations for side street and main street which can be used to optimize the signal timing.

CV technology can provide an alternative method using communications and standardized message sets to request transit signal priority and emergency vehicle preemption (PREEMPT).

Impacts on Intelligent Transportation Systems Planning and Deployment

CV technology combined with improved control software could provide opportunities to automate real-time operations and improve upon the adaptive control systems that exist today. Ultimately fewer resources could be expended on signal operations and retiming.

Impacts on Data

Data from CV has the potential to improve arterial operations significantly, at a low cost. This premise will depend on many factors, like CV penetration rates, data ownership, management, and integration. Best-practices will likely define data management frameworks as research continues to develop in this area.

A relatively small market penetration of CV technology may allow agencies to reduce costs currently incurred in specialized data collection activities for asset management.

Impacts on Operations

Reduced crash rates would help first responder agencies stretch their resources and reduce the amount required to replace or repair infrastructure that is often damaged in crashes such as signal supports, signs and streetlights.

CV technology could advance the shift from reactive to proactive traffic management even on arterials with limited ITS infrastructure in place. Having reliable real-time data could enable traffic agencies to consider new operational strategies, shifting from fixed reactive approaches, to more dynamic operations that incorporate the unique conditions of each event.

Roles and Responsibilities

Public sector agencies lead investment in arterial management infrastructure and applications and determine the standards and goals for their utilization. Agencies will need to work with private sector partners in developing and sharing data and gaining access to distribution networks.

Challenges and Uncertainties

Opportunities exist to incorporate the needs of non-motorized users, as noted above. However, there are challenges in providing access; many non-motorized users, for example, may not have the latest smartphone technology. There is also concern that more efficient signal operations may result in increased arterial speeds, increasing the risk to non-motorized users. Further, current cellphone and nomadic device technology does not provide location information accurate enough for most vehicle warning systems. However, if this aspect can be overcome—then pedestrian devices could provide a benefit to the visually challenged and other special needs populations.

Current institutional management of many arterial systems presents a significant challenge. Arterial systems are managed at the State and local level, sometimes both. Arterial corridors may go through multiple jurisdictions with different levels of resources and operating philosophies. Signal equipment is supplied by a variety of manufacturers and there are systems in the field of different vintage. These factors present a challenge in incorporating CV into arterial corridors and realizing the potential benefits.

Today's traffic control systems (including adaptive) largely rely on volume and occupancy—derived from either road loops or the equivalent using out of pavement technology. CV monitoring cannot provide accurate volumes or occupancy—so today's control algorithms need to determine how to use such parameters as travel times and spot speeds to improve traffic flow.

Case Study on Mobile Pedestrian Signal Systems

Installing CV technology on arterial infrastructure and integrating it into traffic signal control could potentially enhance the safety of pedestrians and cyclists. Integration of SPaT/MAP data with advanced vehicle safety systems could potentially help to reduce incidents, protect pedestrians and cyclists as well as smooth the path of emergency vehicles. (The SPaT message provides information regarding the signal phase displayed (permitted movements) and the time for each such maneuver—i.e., when the movement will no longer be permitted. The MAP message is required in order for the vehicle to assess its position and determine which signal display (signal group) "controls" the lane the vehicle is occupying. Source: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 44.)

The mobile pedestrian (and bicyclist) signal system (PED-SIG) application allows users to broadcast his/her location and request extend walk (green) time. Users interface with infrastructure through an application on a CV-enabled smartphone. The use case for pedestrians is for senior citizens and the disabled who need more time to cross the intersection. The application also can provide visual and haptic feedback to help visually impaired users. The use case for bicyclists is at actuated intersections where bicycle detection and travel time is not sufficient. The application also can collect data and inform authorities of traffic signals that should be adjusted to better accommodate bicyclists.

Several agencies and companies are working to develop and test PED-SIG technology. The Arizona Test Bed in Maricopa County currently is testing various applications, including a pedestrian mobility application. (Arizona Connected Vehicle Program, Arterial Connected Vehicle Test Bed Deployment and Lessons Learned) The Savari SmartCross is an example of an application to aid visually impaired stakeholders. (PED-SIG is the generic application name, while SmartCross is a specific application developed by Savari.) Finally, the NY Connected Vehicle Pilot Project is equipping 100 visually impaired pedestrians and plans to develop a navigation and crossing aid to assist this population using the SPaT and MAP messages being broadcast on DSRC.

To illustrate the costs of deploying a pilot mobile pedestrian signal system project, a hypothetical project focused on a pedestrian and bicyclist mobility application helps to explore the costs and benefits of PED-SIG. In this hypothetical project and PED-SIG application, a bicyclist or pedestrian broadcasts his or her location information and makes an extension request to the RSU. The user would receive a response if the request was successful. The RSU processes the request and interfaces with the traffic signal controller.

Table 3 presents a high-level estimate of capital costs to deploy CV infrastructure, equipment, and the PED-SIG application associated with this hypothetical project. RSUs would be installed at each of the 10 intersections and pedestrians/bicyclists would be equipped with a CV-enabled smartphone. Each intersection would require a signal controller and backhaul upgrade. While there are separate applications with various mobility and safety features, creating a comprehensive application would require more software development costs. The total budget of this project ranges from $412,000 to $1.1 million.

Table 3. Preliminary cost estimate for mobile accessible pedestrian signal system.
Item Quantity Per Unit Cost Total Costs
RSU 10 intersections $4,100-$21,200 $41,000-$212,000
Signal Controller Upgrade 10 intersections $3,200 $32,000
Backhaul Communications 10 intersections $3,000-$40,000 $30,000-$400,000
Mobile Application Development 1 $300,000 $300,000
Mobile Smartphone Upgrade 30 units $300 $9,000
smartphone Project Total empty cell empty cell $412,000-$1,114,000

(Source: Adapted from: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 44.)

In deploying PED-SIG projects, agencies should take precautions to provide consistent and intuitive information for the safety of all users. For example, if the extended walk time is being granted, the walk countdown and traffic signals need to be coordinated.

Along with the data collected from the mobile applications, surveys also should ideally be conducted to assess both the actual and perceived impact. A secondary performance measure of level of service for motor vehicle traffic also may be useful.

In the short term, CV technology introduces a novel way for road infrastructure to respond to the needs of vulnerable users. Over the medium to long term, as market penetration of CV-enabled smartphones and passenger vehicles increases, the benefits of a connected vehicle environment may be fully realized.

Archived Data Management

One of the most important premises of CV is the ability to have better transportation system data that can be analyzed and used to improve real-time system operation.

Current Services and Trends

Current deployment of CV technology is limited to demonstration projects. Recent pilot deployments in Southeast Michigan have provided large amounts of detailed data regarding the performance of CV communication between both vehicle and the infrastructure. However, this data was collected using on-board flash memory chips necessitating the physical access to the vehicles on a periodic basis—which is not practical for a large scale deployment.

Current FHWA-sponsored pilot projects in New York City, Tampa and Wyoming are building on those findings. The NY and Wyoming projects are collecting this data via the CV communications mechanism and are working out the techniques for accomplishing this. State DOTs are now deploying CV infrastructure in some of their major corridors. At present, there is little information on how these technologies will impact ITS and operating strategies, but agencies can expect new findings over the next several years.

Connected Vehicle Technology Opportunities

CV technology provides a major opportunity to increase the amount and quality of data used for real-time operations, research and evaluation. Combined with data analytics, more scenarios can be evaluated and incorporated into increasingly-sophisticated decision support systems.

CV data can be used to enhance current services and over time replace existing services more cost-effectively. However, CV will produce extremely large quantities of data that will need to be reduced, managed and analyzed in order to provide useful information. There are also issues with privacy and security that need to be addressed.

Impacts on Intelligent Transportation Systems Planning and Deployment

As connected and automated vehicle technologies evolve, it is likely that a mixed-fleet of vehicles including AVs, CVs, and traditional vehicles will share the roadway. Such mixed-fleets could present challenges in terms of real-time operations and infrastructure investments. Here, archived data management would be key to provide insights on the road usage and trends of this mixed-fleet. This information can be used to populate models that help determine the timing and feasibility of important decisions; for example, when is it feasible to set aside an AV-only lane and what reduction can be made in its width?

Impacts on Data

CV-enhanced data streams promise the ability to integrate and utilize real-time data for different agencies' activities and operations. For this to happen, a data management framework needs to be designed, allowing real-time data integration from different data sources (automobiles, transit vehicles, trucks, mobile devices, and infrastructure) and communication channels (Wi‑Fi, 5G, DSRC, and other radio communications). Furthermore, processes need to be defined to ensure high-quality information, efficient data processing, and secure data-sharing procedures.

There is a need to enhance system security to prevent hacking and data tampering, as security concerns continue to increase. Furthermore, the data management system needs to protect users' privacy, promoting safety among the multiple stakeholders involved. Data ownership and usage limitations may impact data availability and usage.

There is a need to define data management standards, allowing agencies to incorporate CV data in their current system architectures. This process will likely be defined in detail as CV technology continues to roll out.

Impacts on Operations

With this enhanced data, agencies may be able to deploy enhanced weather applications, enable real-time signal priority, broadcast reliable traveler information, enhance fleet management applications, and develop safety advisory systems.

More detailed information on traffic impacts of adverse weather, or queuing patterns behind incidents would provide opportunities to improve operating and response strategies. Responder after-action reports regarding incidents or other non-recurring events may be greatly improved with the use of CV data.

Roles and Responsibilities

Public sector agencies are likely to be the primary data managers for ITS applications, though that role may evolve in partnership with the private sector. Current and future agencies' data managers will need to update their skills to efficiently use new real-time data sources and improve the agencies' operations.

Challenges and Uncertainties

Data ownership and use will depend on agreements made through the collection and sharing processes. Public agencies and private stakeholders will need to work together on mutually beneficial agreements regarding data that also protect the data rights and privacy of travelers.

Critical to this aspect of CV deployment will be the cooperation between all parties as to how "probe data" will be supported and what data can and will be collected. While R&D project managers and researchers may sometimes desire to "collect everything," this is not practical due to backhaul limitations, storage limitations, and privacy concerns. Both public agency and private CV stakeholders may benefit from an overall data collection plan which pushes "edge computing" to the field devices and Transportation Management Center (TMC) systems and distributes useful information that can be analyzed to improve the operation and measure the benefits.

Case Study on the U.S. DOT Connected Vehicle Pilot in Wyoming

CV data may be used to enhance current traffic management services, and, over time, potentially change the way certain services are performed. However, CVs will likely produce extremely large quantities of data that will need to be condensed, stored, secured and analyzed in order to provide useful information and measure performance. The three CV Pilot Deployment Programs in Wyoming, Tampa, and New York City have released Data Management Plans and Data Privacy Plans in order to provide a framework that addresses these issues and can be adopted by other agencies looking to pursue CV deployments.

The program led by Wyoming Department of Transportation (WYDOT) is intended to develop a suite of applications that utilize vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication technology to enable overall improvements in WYDOT's traffic management and traveler information practices to reduce the impact of adverse weather on travel in the I-80 corridor. These applications support a flexible range of services from advisories, roadside alerts, parking notifications and dynamic travel guidance. Information from these applications is made available directly to the equipped fleets or through data connections to fleet management centers (that will then communicate information to their trucks using their own systems). The pilot includes the deployment of approximately 75 RSUs and 400 OBUs.

The following is a summary of WYDOT's CV data protection and security concept (Federal Highway Administration. Connected Vehicle Pilot Deployment Program Phase 2: Data Management Plan—Wyoming. Report No. FHWA-JPO-17-470. April 2017.):

  • WYDOT hosts a relational database management system responsible for the storage and distribution of all CV data. This system uses persistent identifiers that are available throughout the lifecycle of the data. CV data placed in this data warehouse will be retained for the period of the pilot. WYDOT has adequate online storage so that archiving will not be necessary during the pilot.
  • All server systems within the data center, including the systems that support the relational database management system, will have an operating system (OS) and application patches applied on a regular basis. Additionally, critical patches are installed as soon as practical. These servers have physical data protection implemented with RAID (Redundant Array of Independent Disks) 5 and a hot spare drive. A Secure Network Monitoring Protocol tracks and notifies WYDOT maintenance staff of drive failures.
  • Critical systems are maintained in geographically separate cities for redundancy and to ensure systems can be recovered in the event of a disaster.
  • Backups will be performed on a daily basis and stored in a fireproof locked vault/safe. All information on backup media will be encrypted, whether the backup media is part of WYDOT's rotation or a cloud hosted service. Media retention is planned to be a minimum of three months.
  • Database backups are currently maintained for several weeks and include a combination of internal binary-level backups and exports.
  • Data administration for the data warehouse is controlled by the data warehouse administrator. Developers who access the database must have a reason to access the data and sign a Computer Environment Access and Non-Disclosure Agreement with WYDOT. Developers and consultants will be assigned unique database accounts with appropriately restricted access to information.
  • The relational database management system will implement data encryption and audit logging for Personally Identifiable Information (PII) related information.

The Wyoming CV Pilot data that will be collected to support performance measurement and evaluation are grouped into the following four categories (detailed data elements, source, and frequency are listed in the Data Management Plan):

  • System Data—Data collected from vehicle systems and CV Pilot systems.
  • Non-System Data—Data collected from external systems and databases necessary to support performance measurement.
  • Survey and Interview Data—Data collected through electronic surveys of commercial vehicle fleet managers and truck drivers. Additionally, data that may be collected through in-person interviews of WYDOT personnel and other stakeholders.
  • Modeling and Simulation Data—Data supportive of modeling/simulation activities during performance measurement and evaluation.

The approach to developing the data storage estimates needed to support future evaluation of the pilot program (listed in table 4) was based on initial analysis of likely frequency of certain events happening. These estimates represent a total data storage size estimate for all 75 RSUs and 400 equipped fleet vehicles and commercial trucks over the 18-month demonstration period.

Table 4. Wyoming Department of Transportation connected vehicle pilot deployment program preliminary data size requirements.
Data Category Total Data Assumptions/Comments
Sent basic safety messages (BSM) stored on vehicles 200GB BSM JavaScript Object Notation (JSON) compressed option
RSUs collection of stored BSMs 3TB All 75 RSUs
Interactions between CVs 20-50TB Dependent on CVs traveling within range of each other and sharing information
Environmental sensor data 25GB Estimated 50 vehicles with sensors
Traffic management data 15GB TMC inputs and outputs
Pikalert data
(The Pikalert System supports the integration and fusion
of CV and non-CV weather data to develop alerts and advisories
regarding adverse weather conditions along I-80.)
30GB Forecasts and Motorist Alerts and Warnings
Traveler information messages 5GB Sent from TMC
WYDOT TMC systems 20GB Includes some non-system data
Speed and crash data 10GB Supporting safety evaluation

(Source: Federal Highway Administration. Connected Vehicle Pilot Deployment Program Phase 2: Data Management Plan—Wyoming. Report No. FHWA-JPO-17-470. April 2017.)

The evaluation efforts will measure the level of success of the CV applications deployed in Wyoming through these main performance measures of interest:

  • Improved road weather condition reports received into the TMC.
  • Improved ability of the TMC to issue general alerts and advisories.
  • More effective dissemination and receipt of Infrastructure-to-Vehicle (I2V) and V2I alert/advisory messages from the TMC.
  • Improved information to CV fleet managers.
  • More effectively transmit and receive V2V messages.
  • Automated emergency notifications of a crash.
  • Improved speed adherence and reduced speed variability.
  • Reduced vehicle crashes.

The data in motion is protected by Security Credential Management System (SCMS) signing for all CV wireless communications and encryption for non-broadcast communications. The data that connects third parties to the WYDOT data center will be transmitted over encrypted Secured Socket Layer (SSL) tunnels. This will provide access to the Commercial Vehicle Operator Portal (CVOP), REST (Representational State Transfer) service end points and other Web sites that need protection (not for general public access). For back haul connections from RSUs and traditional ITS equipment, data will be protected with Internet Protocol Security (IPSEC) Virtual Private Networks (VPN) or private networks. WYDOT will host a relational database management system responsible for the storage and distribution of all CV data. For the CV Pilot program an analysis of each data field will be performed. If it is determined that the field could contain sensitive, proprietary, or PII, the field will be marked and any data added or stored to the field will be required to be encrypted. (Federal Highway Administration. Connected Vehicle Pilot Deployment Program Phase 2: Data Privacy Plan, Version 2—Wyoming. Report No. FHWA-JPO-17-469. April 2017.)

Public Transportation

Current CV-related research in this ITS category focuses primarily on enhancing current ITS services in public transportation with CV capabilities.

Current Services and Trends

The transit-focused services that will likely be impacted by CV technologies the most include Computer Aided Dispatch (CAD) and Automatic Vehicle Location (AVL). Although these services are currently being provided as an integrated solution for transit services, it is expected that CV capabilities would allow agencies to enhance such services. Transit Signal Priority (TSP) is being implemented in many cities, particularly where Bus Rapid Transit or exclusive lanes are being provided. Implementation of CV technology on these routes could potentially enhance TSP capabilities. Transit agencies are beginning to test automated and semi-automated systems in confined areas such as campus settings or airports. If these tests are successful, these technologies may be used more in regular service, potentially requiring additional infrastructure support.

Connected Vehicle Technology Opportunities

Since the number of vehicles in any transit fleet is limited and under central control, full market penetration can likely be achieved quickly and major transit routes could receive priority for installation of CV infrastructure.

CV technology could enhance current operations and safety through communication with roadside units and other vehicles. This could improve the effectiveness of TSP operations and also help identify potential safety hazards such as obstacles in a bus lane or pedestrians in crosswalks. Specific CV applications are being developed through U.S. DOT for transit safety including forward collision warnings and curve speed warnings. Other safety applications are designed to detect vulnerable users including bicyclists and pedestrians in crosswalks.

Agencies are beginning to use ridesharing services for first mile/last mile applications. Installation of CV technology at key transfer locations could improve coordination and provide passengers with more accurate wait time information.

CV-enabled transit services will likely be an important data source for transportation agencies. They can serve as effective probe vehicles for both transit and roadway operations since they are continuously on the road.

Impacts on Intelligent Transportation Systems Planning and Deployment

By adopting CV technology, transit agencies could potentially improve service reliability through the integration of their services with other transportation alternatives, such as ridesharing, ultimately making public transportation more attractive to a wider range of users.

Overall agency costs may be reduced if CV technology allows functions such as vehicle tracking and dispatch and TSP to be implemented and operated more cheaply. Greater operational efficiency could also reduce resource requirements.

Impacts on Data

Enhanced AVL and other real-time location and speed data on fleet vehicles will likely support better routing and operations. Enhanced data streams would need to be collected, managed, and archived. Data could be shared with the public to enhance service. Over time, data may be able to support more rigorous operational analysis.

Impacts on Operations

Transit agencies may have the opportunity for more active service management using enhanced real-time location and congestion data. Vehicles could potentially be rerouted more easily with the updated traveler information immediately and widely disseminated to the public.

Transit agencies may have greater opportunity to interface with other agencies involved in active roadway management such as TMCs. This would support event planning and emergency operations.

Roles and Responsibilities

Transit agencies have the potential to lead the deployment of CV equipment on fleet vehicles and design of data collection, management, and analysis processes. In some cases, transit agencies may deploy ITS infrastructure with CV capabilities. In other instances, transit agencies may partner with roadway owners and operators to ensure interoperability. The private sector will continue to play a major role in transit data aggregation, distribution, and supply.

Challenges and Uncertainties

Some of the safety applications being developed will likely require a high market penetration of CV technology among other roadway users. This will take time, and current technologies may become obsolete in the meantime. This is a significant challenge for agencies considering these investments.

Decisions on which parts of the infrastructure are prioritized for CV technology deployment should be coordinated with roadway operations agencies.

Many transit agencies are limited in their ability to procure new technology, by either low-bid requirements or specifications that have not incorporated these technologies.

Case Study on Transit Signal Priority

Many transit agencies use TSP as a way to improve on-time performance and reliability. Transit buses use emitters to send a request to traffic signal controller boxes for signal priority; these process the request and modify the signal cycle accordingly. Typically, TSP logic is to temporarily extend or provide an early start of the original green time. The decision to grant priority and which logic to follow is based on various inputs such as schedule adherence, traffic conditions, bus location, etc.; however, inaccurate and outdated data results in underutilized green times and unnecessary adverse impacts on side streets. (Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 50.)

CV technology can potentially introduce a more integrated means to request and grant TSP. The traffic signal system will have more accurate data and enhanced awareness of existing conditions (e.g., traffic volume). CV technology has the potential to allow messages to be sent with low latency 10 times per second; those messages can include other data such as vehicle speeds and brake status. Furthermore, CV technology could enable traffic controllers to better handle multiple TSP requests. To enhance safety, emergency vehicle preemption may be integrated on the same communication platform.

Mid-Atlantic University Transportation Center (MAUTC) is active in researching CV-based TSP. A study that evaluated new TSP strategies based on CV technology found in simulations significant improvements in reducing bus delay while minimizing side street impacts. Ongoing research at MAUTC will continue to develop these concepts, including by performing an operational field test. (MAUTC, Transit Signal Priority with Connected Vehicle Technology.) The CV Test Bed in Arizona's Maricopa County has concluded from preliminary results that CV technology is a viable medium for traffic signal priority.

To illustrate the costs of deploying a pilot CV-based TSP project, a hypothetical TSP project helps to explore the costs and benefits of this technology. In this hypothetical TSP application, a transit vehicle OBU would send a request for extended green-light to an RSU. The RSU would then process the request and interface with the traffic signal controller. (CVRIA, Transit Signal Priority.)

Table 5 presents a high-level estimate of the capital costs to deploy smartphone infrastructure, equipment, and the CV TSP application associated with this hypothetical TSP project. RSUs would be installed at each of the 10 intersections, while aftermarket OBUs would be installed on each of the five transit vehicles. Each intersection would require a signal controller and backhaul upgrade. The total budget of this project would range from $243,000 to $694,000.

Table 5. Preliminary cost estimates for connected vehicle transit signal priority.
Item Quantity Per Unit Cost Total Costs
RSU 10 intersections $13,100-$21,200 $131,000-$212,000
Signal controller upgrade 10 intersections $3,200 $32,000
Backhaul communications 10 intersections $3,000-$40,000 $30,000-$400,000
Transit Vehicle OBU 5 vehicles $10,000 $50,000
smartphone Project Total empty cell empty cell $243,000-$694,000

(Source: Adapted from: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 50.)

In the short term, CV TSP could provide similar functionality as current TSP systems.

Emergency Management Strategies

One of the categories that is not usually mentioned while discussing potential CV impacts is its effect on emergency management systems. CV may have the potential to improve how transportation agencies respond to different emergencies, potentially enhancing the transportation system resiliency and reducing the emergency impact.

Current Services and Trends

Close coordination between emergency managers and transportation management centers, along with advances in communications, has enabled emergency situations to be addressed more effectively. TMCs, for example, have taken a larger role in supporting evacuations with their detection and surveillance capabilities. New technologies are already beginning to work their way into this area, with Unmanned Aerial Vehicles (UAVs) being considered to provide surveillance of areas that are not reachable due to disasters such as floods, earthquakes or landslides.

Connected Vehicle Technology Opportunities

CV technology may help improve the level of information provided to transportation and emergency managers during emergencies. Evacuation routes may not have detection or CCTV, but the combination of V2I and V2V technologies could be used to collect information on evacuation routes and to provide tailored information back to vehicles. For example, CV-enabled vehicles could be guided to shelters with capacity based on their location during an emergency (although there are limitations on existing CV technologies and issues related to private and subscriber-based information dissemination networks that would need to be overcome in this example).

CV technologies could also support the adjustment of evacuation routes and the repositioning of emergency resources "on the fly" by providing more detailed information on traffic conditions. If a key evacuation route freeway fills up for example, traffic could be re-routed to a parallel arterial and signal timing adjusted based on anticipated flows.

In cases of truck accidents or potentially hazardous spills, emergency personnel could obtain information from the vehicle to identify what substances are involved and what resources are needed to respond.

Impacts on Intelligent Transportation Systems Planning and Deployment

Agencies may want to consider the role of CV in emergency planning and ITS deployment along critical evacuation corridors.

Impacts on Data

CV may increase the amount of data that can be collected from the field remotely and also allow communications directly into vehicles. This may reduce the amount of resources required in the field and allow these resources to be dedicated to faster recovery and restoration of infrastructure.

Archived CV data may be valuable in after-action reports and ongoing efforts to improve emergency response plans.

Impacts on Operations

Transportation and first responder personnel already work together closely in emergency situations, but the availability of richer data sources may allow them to combine resources even more effectively, thus reducing cost of response.

Agencies need to ensure the protocols and operational capacity are available to use CV-enhancements in the event of an emergency.

Roles and Responsibilities

Public sector agencies will likely continue to be the focal point of emergency management, though increased partnership with private sector entities can support widespread and valuable data sharing during emergency situations.

Challenges and Uncertainties

In emergency situations, priority needs to go to response. If strategies are to be enhanced by CV, additional resources may be needed to compile and review the additional information that will be coming from the field as well as to implement optimal strategies.

Deployment of CV technology along evacuation routes may have to compete for resources with deployments on roads that experience more severe and recurring congestion. Maintenance of infrastructure that is only used on rare occasions could be a resource challenge as well.

As with most CV and AV applications, privacy and data ownership issues could impact the ability of public agencies to make use of the data. Agencies need to stay involved in the ongoing resolution of these issues.

Case Study on Emergency Vehicle Preemption

Emergency response vehicles (EV), including police vehicles, ambulances, and fire trucks, provide visual and audio alerts of their presence (e.g., sirens and flashing lights) to prompt surrounding vehicles to clear a path. Unfortunately, the effectiveness of these alerts is limited by background and in-vehicle noise, with drivers sometimes having difficulty determining the source and path of the EV. This confusion has resulted in collisions, creating concerns about both safety and mobility. (Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 26.)

Traffic signal controllers enable signal preemption by detecting oncoming EVs and changing the desired direction to green, while stopping traffic on all other approaches. EVs are equipped with emitters that provide one-way communication requesting preemption. Unfortunately, conflicting requests from multiple EVs needing preemption have resulted in collisions.

A recent study supported by U.S. DOT researched CV-based strategies that could improve safety and response times for EVs in congested urban environments. Through V2V and V2I communication, an EV can broadcast its location, route, and final destination to vehicles and infrastructure in its path. This information can be processed to provide directions that clear a safe path for EVs to their destination. Traffic signals along this path can be optimized to clear downstream intersections. (Improving Travel Times for Emergency Response Vehicles: Traffic Control Strategies Based on Connected Vehicles Technologies) Preliminary results from Arizona's Test Bed in Maricopa County have concluded that DSRC is a viable medium for traffic signal priority.

To help illustrate the costs of an EV preemption pilot project, a hypothetical project in which a Metropolitan Planning Organization (MPO) is implementing the Emergency Vehicle Preemption (PREEMPT) application and related infrastructure is summarized below. Table 6 presents a high-level preliminary estimate of the capital costs to deploy and pilot smartphone infrastructure, equipment, and the PREEMPT application associated with this hypothetical project. The pilot would be on part of the corridor, a 10-mile urban arterial section. There would be about one-half-mile spacing between intersections, totaling 20 intersections. There would be RSUs installed at all intersections and aftermarket OBUs installed on 10 emergency vehicles. The total budget for the initial deployment and testing of the smartphone strategy would range from $433,000 to $1.7 million. There would be other costs not captured here, such as annual operations and maintenance costs.

Table 6. Preliminary cost estimates for emergency vehicle preemption.
Item Quantity Per Unit Cost Total Costs
RSU 20 intersections $13,100-$21,200 $262,000-$424,000
Signal controller upgrade 20 intersections $3,200 $64,000
Backhaul communications 20 intersections $3,000-$40,000 $60,000-$800,000
Light Vehicle OBU with additional features 10 vehicles $4,700 $47,000
smartphone Project Total empty cell empty cell $433,000-$1,657,000

(Source: Adapted from: Federal Highway Administration, Connected Vehicle Impacts on Transportation Planning: Primer (FHWA-JPO-16-420), June 2016, page 26.)

Construction and Maintenance Management Strategies

CV technology has the potential to enhance construction and maintenance management systems. Research found for this category focused particularly in two topics: determining complementary and alternative solutions to enhance road weather data collection services, and enhancing safety in work zones.

Current Services and Trends

U.S. DOT's CV program is involved in the development of applications to support work zone management and maintenance activities, including winter maintenance and other tasks that reduce roadway capacity. CV technology on maintenance vehicles can be used as probes to provide information on roadway conditions. CV technology also provides an opportunity to provide targeted information to motorists, for example, if there is a snow plow ahead but out of sight. There are already efforts underway to implement CV technology in work zones such as in Arizona. These systems will help provide warnings as CV market penetration increases and in the shorter-term can be used to enhance worker safety.

Connected Vehicle Technology Opportunities

Many agencies are starting to bring back detailed weather and roadway condition information from winter maintenance vehicles. Various means of communications are used, including satellite and cell technology. CV technologies provide an opportunity to enhance these efforts; for example, providing warnings and condition information to upstream vehicles via V2I or V2V technology (a function which is currently in the standards development phase).

Temporary CV technology installations could be used to monitor traffic conditions and queues in and around work zones. Movement of construction vehicles and personnel could be monitored to enhance both worker and motorist safety with messages provided to both vulnerable workers and vehicles approaching the zone.

Ultimately some of the more dangerous activities involved with both construction and maintenance may be accomplished with AV. Warnings to approaching traffic would still be required, but these may eventually be transmitted directly to the vehicle. CV technology can work together with advanced traffic management strategies, such as Variable Speed Limits, to enhance work zone safety.

Impacts on Intelligent Transportation Systems Planning and Deployment

CV technologies, through V2I or V2V communications, may allow automatic generation of warnings reducing the workload on TMC operators and field personnel.

CV technology, in a long-run, full penetration scenario, could reduce the need for signs and other field equipment by transmitting warnings and relevant information directly into the vehicle.

Impacts on Data

CV technology presents opportunities for better real-time data on work zone and near work zone facilities. Data resources may support targeted traveler information and active management.

Impacts on Operations

CV technologies have the potential to improve safety through applications of advanced traffic management strategies.

Roles and Responsibilities

Work zone management is largely a public sector role, though partnership with construction firms to ensure interoperability and two-way data flows will be needed for some of the higher level, more active work zone management strategies discussed.

Challenges and Uncertainties

Additional contract requirements to incorporate CV technology may add cost to construction and maintenance activities. Over time, these increases may be offset by reductions in other costs such as temporary signing, but this will require a high market penetration for CV technology.

In providing information on winter conditions, great accuracy is needed especially when there is precipitation and temperatures around freezing. Greater confidence is required in the weather observations coming off vehicles before disseminating traveler information based on the data.

As work zones and maintenance activities are constantly moving, portability of the technology is required and is an important challenge that needs to be addressed. Vendors have been successful in building ITS capabilities into portable installations and will need to do the same in implementing CV technology.

Case Study on Connected Vehicle Work Zone Safety Applications

Work zones disrupt regular traffic flow and can be especially hazardous when drivers are unprepared to respond quickly to temporary traffic control measures. Rear-end crashes (running into the rear of a slowing or stopping vehicle) are the most common type of work zone crash, with the majority of fatal work zone crashes occurring on roads with speed limits greater than 50 mph. U.S. DOT has developed several CV-based strategies to improve safety in these situations, such as Queue Warning (Q-WARN) and Incident Scene Work Zone Alerts for Drivers and Workers (INC-ZONE).

The Q-WARN system provides drivers with a warning of downstream queue backup to allow drivers to adapt, slow down, and prepare to brake. The traffic data used for queue determination may originate from the vehicles, travelers or roadside infrastructure. Vehicles would broadcast their status when certain parameters are triggered such as rapid deceleration and/or low speed relative to the posted speed limit. Traffic data from vehicles can be broadcast using vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) to upstream vehicles and centrally to a TMC respectively. Q-WARN is part of the Intelligent Network Flow Optimization (INFLO) bundle that aims to improve roadway throughput and reduce crashes through the use of frequently collected and rapidly disseminated data drawn from connected vehicles, travelers, and infrastructure. Q-WARN can be used in conjunction with the INFLO Dynamic Speed Harmonization (SPD-HARM) application, in which the vehicle operator can adhere to the dynamically recommended vehicle speed for downstream congestion, incidents, and weather or road conditions in order to maximize traffic throughput while reducing crashes.

A small-scale demonstration of the INFLO prototype system was deployed in Seattle, Washington in 2015. A smartphone graphical display mounted on the dashboard of each CV-equipped vehicle provided drivers with two types of Q-WARN messages: a Queue Ahead message that displayed the distance to the back of the queue, and an In-Queue message that displayed the distance and estimated time to the end of the queue. Drivers could expect to receive messages at least a mile in advance of the back of the queue. Participants in the demonstration saw immediate value in both queue warning message types, stating that the messages allowed them to take action in advance of congestion, reducing the need to slow down or stop suddenly. (U.S. DOT, Connected Vehicle—Mobility.)

INC-ZONE is part of the Response, Emergency Staging and Communications, Uniform Management, and Evaluation (R.E.S.C.U.M.E.) bundle that aims to transform the processes associated with incident management. The CV applications included in this bundle (Incident Scene Pre-Arrival Staging Guidance for Emergency Responders or RESP-STG, INC-ZONE, and Emergency Communications and Evacuation or EVAC) seek to quickly detect and assess incidents and their effects on traffic flow, model the evacuation flow, push information to evacuees, and help responders identify the best available resources and ways to allocate them in the timeliest manner. The INC-ZONE application bundle has two components, one that warns drivers that are approaching temporary work zones at unsafe speeds, and or trajectory; and another that warns public safety personnel and other officials working in the zone through an audible warning system.

The INC-ZONE prototype was developed and demonstrated first in Columbus, Ohio and then at the Maryland Police and Correctional Training Commission's Driver Training Facility in Sykesville, Maryland, both in 2014. The INC-ZONE prototype consisted of an in-vehicle messaging system that provides drivers with merging and speed guidance as they approach an incident zone. The system sends warning messages to drivers if they are arriving at the incident location at an unsafe speed or trajectory, as well as warning messages to on-scene workers.

While demonstration participants believed in the effectiveness of the INC-ZONE application to save lives of first and second responders, as well as motorists, one of the challenges of this demonstration was placing the connected vehicle applications on the responder and oncoming vehicles. Implementing CV messaging between responder and oncoming vehicles to support threat and imminent crash warnings also presented issues. Another challenge and potential improvement area was the implementation of lane-level mapping and an accurate GPS positioning system. The INC-ZONE application needs to be compatible and incorporated into existing responder portable laptops and existing consumer smartphones while using the existing public safety communications equipment to be effective. (Federal Highway Administration. Estimated Benefit of Connected Vehicles: Dynamic Mobility Applications, AERIS, V2I Safety, and Road Weather Management Applications. Final Report. Report No. FHWA-JPO-15-255. August 2015.)

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