2 Background

2.1 History of Project

The purpose of this project is to develop a WRS and assess the operational use of weather information for transportation management, operations, and maintenance.

Funding for the WRS development is provided by the U.S. Department of Transportation's FHWA and MoDOT through a Cooperative Agreement, DTFH61-04-H-00017. MoDOT contracted with Mixon/Hill, Inc. to lead the development of the WRS.

Transportation system operations are very sensitive to weather conditions. However, weather information and information about the impact of weather on the transportation system is currently not well integrated into the operational framework of most state transportation agencies. Today, operations personnel in many state departments of transportation obtain weather information from multiple sources (e.g., NWS, newspaper, local television stations, commercial weather firms, etc.), and, in many cases, this information is non-specific, conflicting, and not tailored to support the needs of the specific decision makers.

The establishment of the FHWA Road Weather Management program within the Office of Transportation Operations signaled that weather has an important impact on operations and that weather and road condition information need to be integrated into operations.

The FHWA, working with state transportation agencies, national laboratories, the National Oceanic and Atmospheric Administration (NOAA), the American Meteorological Society (AMS), the Aurora Program, and others, has raised the awareness of the needs of the surface transportation community for better, more tailored weather and road condition information. The FHWA winter Maintenance Decision Support System (MDSS) project is a good example of a project that has brought stakeholders together to develop advanced road-weather applications tailored for end users. The MDSS project utilized currently available weather data sources and developed advanced capabilities where no off-the-shelf solutions existed. Through an iterative process of development and user feedback, the MDSS prototype successfully evolved into an effective decision support system. State transportation agencies and the private sector are using the MDSS prototype as a template for an operational capability in winter weather maintenance.

The WRS similarly brings together advanced weather and road condition technologies for addressing other operational categories, including traffic, incident, and emergency management, and for broader maintenance activities, beyond winter storm response.

Overall, the development of WRS is an iterative process that has begun with the development, implementation, and demonstration of a prototype WRS. The development of the prototype WRS and the recommendations that have emerged for future system enhancements are described in this report. Future activities could include further development and demonstration of the concepts and components of the prototype WRS; the development of enhanced decision support tools; and the deeper integration of WRS into the maintenance and operations activities of a state transportation agency.

For this project, user-tailored data and products generated by the WRS were provided to MoDOT personnel, allowing them to respond to the effects of changing weather in a proactive manner. The overall scope encompassed transportation system operations, maintenance strategies, and weather information for customers.

Thinking of MoDOT's operational weather information needs, it is easy to focus on severe winter weather and winter storms. The needs at those times, such as deploying plows and choosing the appropriate roadway treatments, are very visible and are understood by the public and practitioners alike.

However, weather information is an operational priority for MoDOT throughout the year. Many of the warm-weather operations that MoDOT performs are also weather sensitive. For example, pavement striping, work zones, emergency repairs, and mowing and brush cutting are all affected by heavy rains, lightning, tornados, strong winds, and extreme temperatures. Consequently, the prototype WRS was intended to support MoDOT's operational needs year round.

MoDOT operates as a decentralized organization with its Central Office located in Jefferson City, Missouri. Major divisions within MoDOT include Administration, Communications, Finance, Operations, Planning, and Project Management. Central Office and district offices operate under similar organizational structures with Central Office providing staff assistance and functional integration for various departmental tasks in the 10 geographical districts. Each district contains about 10 percent of the total road mileage in the state highway system and is under the direction of a District Engineer who is responsible for administering all Department activities in his/her respective district.

MoDOT currently has three operational Transportation Management Centers (TMCs): the St. Louis Gateway Guide Transportation Information Center (TIC), KC Scout Transportation Operations Center (TOC), and Springfield's Ozarks Traffic Information. These TMCs monitor metro-area highways using a range of advanced technologies to provide motorists with real time traffic information and facilitate incident response.

Information on forecast weather and road conditions is an operational priority for MoDOT throughout the year. For example, MoDOT factors weather information into decisions affecting:

• Transportation Management Centers;
• Traffic operations;
• Maintenance operations;
• Construction operations;
• Public information/customer service.

However, MoDOT does not currently have a comprehensive source of weather forecast or road condition information on which to base these decisions. Instead, MoDOT utilizes a small network of 13 Road Weather Information System (RWIS) sites around the state, together with a variety of weather information sources including commercial media, Data Transmission Network (DTN) weather radar, the Internet, and intra-agency radio and telephone communications to gather information¹. Furthermore, weather and road condition information is not currently tailored to meet the individual needs of MoDOT users; nor is it tightly integrated into existing systems used by MoDOT personnel. Indeed, even the most intensive use of weather and road condition information for winter weather maintenance relies heavily on individual experience and established rules of practice rather than automated systems.

2.2 Approach

The prototype WRS was developed using a systems engineering approach for rapid prototyping. Prototyping is the process of building a working model of a system, for the purpose of evaluating potential functions of the final system and refining its design.

User requirements workshops were held with stakeholders from FHWA and the Traffic Division in the MoDOT Central Office and employees in Districts 4 and 9 of MoDOT. These workshops discussed the forecasted weather information needed to plan and schedule work, and the real-time weather information needed to perform work. Divisions represented in the requirements gathering meetings were maintenance, construction, bridge, traffic, and representatives of the transportation management center (TMC). In breakout sessions, each of the activities performed by MoDOT personnel were evaluated for relevance to the objectives of the WRS project. The various MoDOT work activities were discussed in terms of a pre-defined set of weather parameter to determine the impact of that weather element on the work task.

Telephone interviews were held with the MoDOT districts to ascertain the current status of all environmental sensor stations (ESS) within the MoDOT Road Weather Information System (RWIS).

A Concept of Operations (ConOps) was created to articulate the needs of MoDOT weather and road condition information users. The ConOps described how the prototype WRS would be developed and operated to satisfy those needs. The user needs were supplemented through literature reviews and individual interviews with MoDOT personnel, in addition to the user requirements workshops described above.

A System Architectural Description (SysAd) was created to describe the system components and their relationship to one another for the prototype WRS. The architecture of the system was described from multiple viewpoints to capture various stakeholder perspectives. These base system architectural viewpoints are followed by a description of how the prototype WRS fits within the National ITS Architecture and Missouri's regional architectures.

An internal Systems Requirements Specification (SRS) was created to provide a repository for the requirements governing the design of the prototype WRS. These requirements formed the basis for the design verification and validation of the system.

Following these documents, the prototype WRS was designed and created. Because this project was based on rapid prototyping, a formal design document was not created. However, a copy of the code was archived at any point that major changes to the code occurred. During the rapid prototyping period, FHWA and MoDOT evaluated the current state of the system and made recommendations for change. Based on scope, schedule, and budget, the changes were either implemented in the system at that time, or were recommended as future enhancements.

During the latter phases of the development of the prototype WRS, the system was evaluated by FHWA. FHWA provided recommendations for enhancements, all of which were incorporated prior to deployment of the prototype WRS by MoDOT in District 4.

An operator user guide was created that provided a description of the WRS applications, along with step-by-step instructions to use the prototype WRS. A training session was held with MoDOT employees to instruct them on the operational use of the prototype WRS and appropriate applications of the system. During the training session, several recommendations for enhancements were submitted by MoDOT personnel. All recommendations submitted during the training session were incorporated into the prototype WRS and deployed.

During the evaluation period, conference calls and one-on-one meetings were held with selected operators of the prototype WRS. All recommendations submitted during these calls and meetings were incorporated into the prototype WRS and deployed.

Extremely mild winter and spring weather was experienced throughout the prototype evaluation, and regrettably the system could not be exercised to its full potential. As a result, an additional meeting was held with MoDOT stakeholders to evaluate the prototype WRS using both newly-established scenarios and actual prior weather events. The stakeholders, representing urban and rural locations within District 4, included three employees from the TMC (supervisors and operators), three employees from traffic (administration, striping, and signs), four employees from construction (inspector, resident engineers, and district construction engineer), and twelve employees from maintenance (district maintenance engineer, maintenance superintendents, and supervisors). This report documents the results of this evaluation, including recommendations submitted for future enhancements.

2.3 Objectives and Scope

The prototype WRS has been developed and implemented to:

• Aid in the evaluation and assessment using weather information for surface transportation system management, operations, and maintenance objectives; and
• Support effective response by MoDOT personnel to the impacts of weather on the transportation system.

The prototype WRS is designed to:

• Take advantage of operational weather data and products from the NWS;
• Utilize a variety of weather data sources including traditional NWS sources and emerging products such as the NWS National Digital Forecast Database (NDFD);
• Leverage the experiences related to user needs and decision support tools developed in the FHWA MDSS project;
• Provide a framework to develop and demonstrate prototype road-weather products tailored for specific operational categories (e.g., traffic management, maintenance management, and customer service);
• Support the operational decisions of maintenance supervisors and traffic managers in MoDOT; and
• Provide weather data managed by the WRS to TMCs and district maintenance facilities in order to evaluate its effectiveness and to identify the needs for additional weather-related decision support tools for transportation management, operations, and maintenance.

2.4 Operational Policies and Constraints

There are no formal operational policies and procedures that relate to the use of weather information within the traffic management and traffic operations responsibilities of KC Scout. However, if a major weather event (such as a large winter storm) is anticipated in the Kansas City region, MoDOT will prepare for the event by extending shifts within the KC Scout TMC or calling in additional traffic operations and customer service personnel to handle expected workload. This process is somewhat informal and relies on the availability, accuracy, and timeliness of meteorological weather information from principally non-MoDOT sources.

The Maintenance Division of MoDOT provides its managers with "Maintenance Function Planning Guidelines." These guidelines highlight the relationships between maintenance activities and weather and road conditions. For example, the guidelines identify maintenance activities that can be performed on rainy days and provide an overall monthly/seasonal maintenance work scheduling guide. Most importantly, however, the guidelines prescribe necessary weather and road conditions for each maintenance activity. For example, the guidelines specify that the "repair of full depth failures in Portland cement concrete pavement" should only be scheduled when the temperature is 50°F and above, and suggest that this limits the work to mid-March through the end of November.

The maintenance guidelines specify work activities in the areas of:

• Pavement maintenance;
• Pavement preventative maintenance;
• Maintenance of shoulders and approaches;
• Drainage maintenance;
• Roadside vegetation and litter control;
• Maintenance of roadway safety devices;
• Maintenance of bridges;
• Bridge preventative maintenance; and
• Traffic operations (including marking, striping, and lighting repairs).

In addition, the MoDOT Maintenance Division provides its field personnel with an "Operators Guide for Anti-Icing." This guide recommends maintenance actions for preventing the formation or development of packed and bonded snow or bonded ice on the first priority continuous treatment routes during a variety of winter weather events including:

• Light snow storms;
• Light snow storms with periods of moderate or heavy snow;
• Moderate or heavy snow storms;
• Frost or black ice;
• Freezing rain storms; and
• Sleet storms.

This guide describes the initial and subsequent maintenance operations activities for each winter weather event based on observations of pavement temperature ranges and trends.

The MoDOT Construction Division is also responsible for a variety of activities that are sensitive to weather and road conditions. However, unlike the activities of the Maintenance Division, these activities are conducted primarily by outside contractors. It is MoDOT's policy to leave decisions relating to the scheduling and performance of the construction activities to these contractors.

2.5 Description of Normal Modes of Operation for Weather Information

With no existing integrated statewide system for delivering weather and road condition information to the various MoDOT users, the multiple existing sources of information are used only in an advisory form as input to operational and short-term planning activities. Because information from the existing published sources may be incomplete or conflicting, individual users tend to rely on experience and established, but undocumented, rules of practice in their decision making. Depending on the direction of a weather event, districts may exchange information with each other on an informal basis.

Weather information is generally used reactively rather than proactively. Construction and maintenance crews report to job sites and assess the weather conditions upon arrival. If work can start, they start and continue work as long as weather conditions permit.

Long-term weather forecasts are considered too unreliable to be used for long-range maintenance and construction planning. In most cases, even seven day forecasts are considered too unreliable for use in short-term planning. The major exception is that seven day forecasts for ice or major snow storms will initiate maintenance preparations for the storm events. When 24-hour forecasts include snow and ice storms, work crews are put on notice and schedules are prepared for 24 hour operation for the snow/treatment crews.

At the TMCs, operations are relatively unaffected by weather. Snow crews may use TMC facilities and CCTV systems to monitor road conditions on the freeways, but the TMC websites do not publish weather or road condition information. TMC operations policies allow operators to post tornado warnings on DMS signs in counties that are under a warning, but there is no current procedure or mechanism for notifying the operators that such warnings are in effect. Operators are notified and can post warnings on the DMS signs when snow plowing operations are underway on the freeways.

Customer Service does not volunteer weather information to the traveling public, but will relay information from the DTN forecasts and MoDOT road condition website to customers when weather information is requested. Customer Service hours are extended to a 24/7 operation during major winter storms.

2.6 User Classes and Other Involved Personnel

There are four primary existing weather and road condition information user classes within MoDOT:

• Maintenance operations personnel who use the various existing weather and road condition information sources in their year-round maintenance planning and winter weather response activities;
• Traffic operations personnel who utilize weather information in their real-time operational activities (for example, the KC Scout TMC displays the NWS at Pleasant Hill, MO on their consoles as needed during weather events);
• Customer Service personnel who use information from the MoDOT road condition information website to answer questions from the general public; and
• Construction operations personnel who have access to weather and road condition information but who utilize the information to the least extent. Since the Construction Division relies on contractors to perform much of its work, it is MoDOT's policy not to interfere with their planning and scheduling activities. MoDOT construction personnel do not volunteer weather information to contractors; providing weather forecast information to contractors is considered a liability and MoDOT prefers that contractors obtain weather information directly from external weather information providers. MoDOT inspectors, within construction operations, use weather information to verify that contractors are performing their activities based on the published weather guidelines.

In addition to the internal MoDOT users, there are two other groups of involved personnel: the traveling public and commercial vehicle operators. These groups are indirect consumers of MoDOT weather data, receiving weather and road condition information from the MoDOT website, from Customer Service personnel who answer calls, and from the DMS signs when weather warnings are published.

Other agencies such as emergency services personnel, HAZMAT, Highway Patrol and local law enforcement do not consider MoDOT as a source for immediate or short-term weather information; they tend to ask their own dispatchers for weather information.

2.7 Support Environment

MoDOT personnel receive support for all information technologies from the Information Systems Division.

DTN provides service and support for the equipment furnished as a part of its contract.

Most of the state's RWIS installations were installed and maintained under a contract with SSI. The maintenance of the weather instrumentation is considered relatively low priority and is usually conducted on an annual basis rather than on a remedial basis. It can be weeks or months before a failed weather instrument is repaired or recalibrated.

Several of the state's RWIS installations were installed by District offices for special purposes. The budgets and expertise for maintaining the weather instruments were rarely in place and, as a result, many of these installations have fallen into disrepair. The RWIS stations and the data received by MoDOT from those stations are not standardized, further complicating attempts to maintain the equipment.

Computers, software, network equipment, radio and satellite equipment, and video equipment installed in the TMCs are supported by local MoDOT District technicians or are supported under specific support contracts for each system where MoDOT lacks the staff or expertise to support the system internally.

The state currently has no trained meteorological staff to support forecasting, RWIS operations, or any other weather-related systems.