Managing Travel for Planned Special Events

Chapter Six. Traffic Management Plan
Page 8 of 9

En-Route Traveler Information Plan  

Overview

The dissemination of traveler information for a planned special event is an integral part of operating and managing the transportation network. The following three issues must be considered in developing and maintaining the event plan:

• Stakeholders – The information needs of travelers extend well beyond an agency's infrastructure and include other jurisdictions' highway facilities, transit facilities, airports, etc. The private sector should also be an active partner in the traveler information process and must be included as a stakeholder.
• Evaluation – Care should be taken not to overestimate the benefits achieved by the implementation of information dissemination components in the plan. Specifically, it is important to recognize that travel patterns are quite dynamic and that some drivers will divert naturally when they encounter congestion regardless of whether or not they receive information beforehand about that congestion. A Washington, D.C. Advanced Traveler Information Systems (ATIS) study revealed:
  • If ATIS deployments are evaluated purely on time-savings, the benefits of ATIS will likely be grossly underestimated.
  • ATIS users value improved travel reliability. The value of improved on-time reliability is not easily nor directly monetized, but it is clear that many types of travelers can benefit from ATIS.
  • Improved reliability and predictability of travel are also likely good surrogates for reduced driver stress. From this common sense perspective, it is clear that the benefit of improved travel reliability and predictability from ATIS will outweigh whatever small return is generated from the monetization of aggregate travel time reductions.
• Performance Measures – In order to assess the extent to which the traffic management plan efforts within are meeting goals and objectives, a set of performance criteria and measures-of-effectiveness pertaining to these efforts must be identified. Relative to coordination and information dissemination, performance criteria have three different, yet interrelated, dimensions that are of interest:
  • Information credibility – An information dissemination tool must be credible to travelers if it is to be utilized and have an impact upon traffic operations. The following criteria define how credibility is established: (1) the information must be accurate, (2) the information must be timely, and (3) the information must be relevant to its intended audience.
  • Market penetration – Market penetration refers to the percentage of the potential audience reached by the information dissemination efforts. Performance criteria regarding market penetration may be appropriate for evaluating certain system goals and technologies, particularly those emerging as part of ATIS. It is expected that some technologies, such as in-vehicle dynamic route guidance, will require only limited market penetration in order to achieve operational benefits.
  • Other operational benefits – Other technologies, such as information kiosks in major traffic generators, may require agencies to strive for as great a market penetration as possible in order to distribute the information to a wider audience and possibly attract private sector advertising and sponsorship.
  • Traveler response – Ultimately, the purpose of providing information to travelers is to effect some change in traveler behavior that will cause an improvement in safety or operations. Thus, performance measures are also needed to determine the extent to which information dissemination accomplishes this purpose. Changes in traveler mode, departure time, and route (if appropriate) are appropriate for evaluating the effectiveness of real-time, travel-related information. However, it may be very difficult and expensive to obtain actual data for these measures. Traveler opinions about the effectiveness of the information being provided can be another important evaluation measure.
  • It is important to recognize that because of the complex travel patterns of travelers at any point in the roadway, it may not be possible to adequately measure the overall effects of many types of information or dissemination modes upon traffic volumes, speeds, or delays. The day-to-day variances in travel patterns themselves may mask the effects of any information disseminated during a specific event such as an incident, particularly if the information is intended for a very specific audience (such as vehicles within a traffic stream destined for a specific downstream exit).

Information Needs

En-route traveler information can provide event patrons and other transportation system users with current roadway and transit information while traveling en-route. Information is typically provided via devices deployed along the side of the roadway, or from devices mounted on the dashboard of the vehicle. Along the roadway, changeable message signs and highway advisory radio messages typically provide information regarding an upcoming planned special event, including current conditions related to the special event such as traffic congestion, incident and construction locations, weather advisories, parking availability, and alternate routes. In-vehicle and personal mobile devices can provide a variety of en-route traveler information to both the traveler as well as transportation providers. Sophisticated route guidance systems can assist motorists in route planning as well as providing timely directions via a computer synthesized voice.

Static Signing

Static signs can be used for event management to inform travelers of an upcoming planned special event, to identify park & ride lots, and to guide motorists to particular locations. It is not uncommon for agencies to use static signing in special event management for the following purposes:

• Notify travelers of a future special event.
• Notify travelers of future facility changes for the event such as lane closures or occupancy restrictions.
• Identify special alternate routes for the event.
• Guide travelers to parking or park & ride lots.

Transportation incident responders utilize static signing in day-to-day operations to trailblaze motorists along an alternate route or venue access route. These are temporary signs, mounted on fold-away supports, along the shoulder of the roadway or at exit gores to direct motorists to alternate routes as a matter of typical traffic management or in response to an incident and redirecting of traffic.

Changeable Message Signs

One of the most fundamental technologies available for disseminating traffic-related information from the roadside is that of changeable message signs. CMSs are sometimes referred to as dynamic message signs or variable message signs. CMSs are programmable traffic control devices that can usually display any combination of characters to present messages to motorists. These signs are either: (1) permanently installed above or on the side of the roadway, (2) portable devices attached to a trailer, or (3) portable devices mounted directly on a truck and driven to a desired location. Portable CMSs are much smaller than permanent CMSs and are oftentimes used in special event situations, highway work zones, when major crashes or natural disasters occur, and emergency situations.

When installed, CMSs become a part of the total motorist information system. Thus the information presented on CMSs and the placement of the signs must be consistent and compatible with static signs. Highway signs – both static and dynamic – must project a message so that the driver can:

1. Detect the sign,
2. Read and understand the sign,
3. Make appropriate decisions based on the information gained from the sign, and
4. If necessary, initiate a control response, and complete the required maneuver.

CMSs perform a critical role in special event management. Such signs can furnish motorists with real-time information that advises them of a problem and in some cases, a suggested course of action. CMSs are also used to improve motorist safety and reduce traffic congestion and delay during events. CMSs can be used to manage traffic by displaying the following types of messages:

• Early warning messages give motorists advance notice of slow traffic and queuing ahead and are effective in reducing secondary crashes. When used in freeway work zones, early warning messages also give notice of new detours, changes in alternate routes, changes in lane patterns, special speed control measures, etc.
• Advisory messages provide motorists with useful information about a specific problem along their route. This information allows motorists to change their speed or path in advance of the problem area, or may encourage them to voluntarily take an alternate route to their destination.
• Alternate route messages influence motorists to travel to their chosen destination by using different routes than originally intended. The alternate route is one designated by the transportation agency. In cases when the freeway is physically closed as a result of construction, crash, or natural disaster, the motorists are notified that an alternate route must be used.

The most critical locations for installing permanent CMSs are in advance of interchanges or highways where drivers have the opportunity to take some action in response to messages displayed on CMSs. In many special event cases, permanent CMSs are already strategically located to advise event patrons of special conditions and non-event motorists of alternate bypass routes. Figure 6-56 shows a permanent CMS over an arterial located adjacent to a stadium venue and serving venue parking areas.

Figure 6-56. Permanent CMS Over Stadium Access Road

A CMS should not compete with existing roadway signs. In general, a CMS should be permanently installed at the following locations:

• Upstream from major decision points (e.g., exit ramps, freeway-to-freeway interchanges, or intersection of major routes that will allow drivers to take an alternate route)
• Upstream of bottlenecks, high-accident areas, and/or major special event facilities (e.g., stadiums, convention centers)
• Where regional information concerning weather conditions such as snow, ice, fog, wind, or dust is essential

Portable CMS

The use of trailer-mounted CMSs provides an agency with a great deal of flexibility. The signs, which are typically much smaller than permanent, over-the-road CMSs, are used most commonly for temporary applications. As such, portable CMSs are very suitable for special event management. They are usually diesel- or solar-powered and use wireless (cellular) communications to a central management point, making them a very attractive and flexible tool.

Portable signs are usually located at the side of the road and do not sit as high as an overhead sign, which can impair drivers visibility. Most are 3-line, 8 or 9-character signs, and although most have the capability of displaying multiple phases, they tend to be used with simple short messages to allow drivers to read and comprehend the message.

Highway Advisory Radio

Although not as widely used as changeable message signs, highway advisory radio is another means of providing highway users with information in their vehicles. Traditionally, information is relayed to highway users through the AM radio receiver in their vehicles. Upstream of the HAR signal, users are instructed to tune their vehicle radios to a specific frequency via roadside or overhead signs. Usually, the information is relayed to the users by a prerecorded message, although live messages can also be broadcast.

Highway advisory radio is an effective tool for providing timely traffic and travel condition information to the public. It has various advantages and disadvantages. Its most important advantage is that it can reach more travelers, or potential travelers, than the other roadside technology, changeable message signs. While CMSs reach only those motorists at a particular point, and can only convey a short message, HAR has the advantage of being able to communicate with any person in the HAR broadcast range. Furthermore, the amount of information that can be conveyed to the user is much greater. Its primary disadvantage is that it is restricted to low power, and this can lead to poor signal quality (since many outside forces affect the signal, such as weather) and, therefore, poor listener levels.

HAR is an element of the Federal Communication Commission's (FCC) Traveler Information Systems (TIS) designation. They are permitted under strict FCC guidelines and regulations associated with technology and operations. They are licensed as a secondary user, which means simply that they cannot interfere with a primary user, i.e., a commercial broadcast station. As a secondary user, HAR broadcasts are restricted in signal strength, a level that limits their transmission range to no more than three or four miles from the transmitter. A number of technologies are available for HAR transmission, using both AM and FM bands.

Typically, HAR has been implemented using 10-watt AM transmitters. This is because, beginning in 1977, it was the only technology permitted by the FCC for traveler information. As such, this technology implementation has also proven to be the most effective. Other means involve very-low power AM transmission, where multiple transmitters are spaced closely together to form a large area of coverage. This application, however, has not proven very successful. As late as 2000, the FCC ruled to allow the use of low-power FM transmission for TIS. This technology has limited application to-date.

Urban areas typically present a unique set of challenges to HAR application, which can hinder downtown event management. Tall buildings present an obstacle to uniform transmission since the FCC restricts antenna height to approximately fifty (50) feet. High-power electric lines can incur noise on the transmission that negatively impacts broadcast quality.

Deployment Strategies

HAR can be broadcast in two ways: Point or Wide-Area coverage.

• In Point broadcast, a single transmitter is used to broadcast over a given area. This is typically used at diversion points in advance of areas of recurring congestion to notify motorists of queues and congestion. This type of implementation is popular with travelers because the information is specific to them. This is the most common application for HAR, and it typically utilizes 10-Watt transmitters. It is the simplest to manage in terms of equipment to maintain.
• Wide Area Broadcast transmits a signal to a larger coverage area using multiple synchronized transmitters. This is an effective strategy when a single message is applicable to a large coverage area and the coverage area is sufficiently large for a motorist to hear the longer message length. The fact that a long single message, that is pertinent to specific travelers for only a part of the message, is indeed a disadvantage. Studies have shown that travelers want brief, specific information, pertinent to their location and situation. They are not likely to listen for long periods of time until their information is broadcast. Technically, synchronization is difficult to accomplish between transmitters because both the time and repeated voice signal must be in sync.

Both of these applications are practical and viable for planned special event management.

Portable and Mobile Systems

Portable systems permanently installed on trailers and mobile systems installed on service or maintenance vehicles can be of value in providing timely dissemination of information to motorists during short-term deviations from normal highway conditions, or more specifically, during planned special events. These systems can be solar powered, generator powered, or battery powered.

Portable and/or mobile systems could be set up at decision points where a route guidance system directs motorists to an alternate route. This will increase motorist comfort level by reinforcing their confidence that they are following the alternate route instructions correctly.

HAR signs, indicating the frequency at which traffic information is available, are typically installed throughout each zone. These signs usually include flashing beacons that are activated only when a message of some predetermined level of importance is being broadcast and a legend reading (or similar) "TRAFFIC ALERT WHEN FLASHING." This technique permits the system to continuously broadcast "default" messages in each zone during non-congestion periods, while alerting the motorist to an urgent/emergency message by turning on the flashing beacons. Thus the system prevents motorists from tuning to the HAR frequency only to hear the default message time and time again, situations that could negatively impact system credibility.

Changeable message signs can also be used to alert the motorist to the broadcast of a message of the utmost importance. These signs can be controlled through phone lines, or with cellular or paging technology, and can be solar powered with battery back up. They offer a great deal of flexibility, by allowing only the pertinent signs to be activated. For instance, while two signs (one in each direction) may be associated with a particular transmitter, only one would be activated for a downstream incident, thereby eliminating any loss in credibility due to providing a message that is not applicable to one of the directions of travel.

Media

The public has learned to depend upon the media to provide them with "almost" real-time traffic information. Commercial radio has proven to be a good means of providing travelers with traffic information both in and out of their vehicles. Traffic and roadway condition reports have become standard programming items on many commercial radio stations. Commercial radio has the best potential of reaching the greatest number of commuters, since most of them have radios in the vehicles they drive to and from work. It is not uncommon for planned special event stakeholders, including public agencies, to partner with a commercial radio station (or for a commercial radio station to sponsor a special event) to enhance the information dissemination related to the event and its transportation conditions. Care should be taken to ensure that the information disseminated reflects current traffic conditions and is credible.

Other Technology Applications

Other technology applications include:

• Cellular telephone-based systems
• 511
• In-vehicle displays
• Subscription services
• Personal data assistants

Telephone Based Traveler Information

An in-vehicle communication technology that has seen dramatic growth in the past few years is cellular telephones, which gives the motorist the ability to call special "hotline" systems for traffic information from within their vehicle. Originally, these systems allowed motorists and transit users to call for information to assist in pre-trip decisions from their homes. Information can now be accessed en-route via cellular telephone, and decisions can be made whether to alter travel routes. The creation of call-in systems has been a popular traffic impact mitigation strategy for many major urban freeway reconstruction projects in recent years.

This type of in-vehicle communication has the advantage over HAR of giving the motorist some control over the type and amount of information he/she wants to obtain through the touch-tone menus. In addition, it is also possible to generate two-way communication between the motorist and the information source.

Recommendations for establishing cellular telephone-based systems include the following:

• The call must be toll-free to users.
• The telephone number must be easy to remember and dial.
• The information must be concise.
• If a menu system is used, a long and tedious menu selection process should be avoided.
• A sufficient number of telephone lines should be provided to prevent the majority of users from receiving a busy signal.
• If a system is going to be used to gather information from users, there must be a method of ensuring the accuracy of the incoming information.
• "Official" use of tipster information should include procedures for verifying that information.
• If incident information is to be received, a human operator is recommended so that secondary questions can be asked to clarify confusing or unclear reports.

As with HAR systems, this technology also requires action by the motorist to access information. There are also significant operating costs associated with this technology, as any calls made using cellular telephones must be paid for by either the motorist, or a public agency, or else absorbed by the corporation providing cellular telephone communication capabilities in the region. Finally, there is some concern that cellular telephone usage while driving may degrade motorist attention and operating capabilities. Manufacturers have developed "hands-free" telephones that allow motorists to listen and talk without holding the telephone receiver, although the need to push the telephone buttons to go through a menu of information operations can defeat the "safety" purpose behind hands-free devices.

Many metropolitan areas established cellular "hotlines" for motorists to call in and report traffic incident information to the highway agency. Examples included #77 and *SP. However, the establishment of the 511 national traveler information number is envisioned to replace these already established numbers.

511

Understanding the importance of consistency and simplicity in providing telephone-based traveler information, in 1999, the U.S. Department of Transportation (USDOT) petitioned the FCC to designate a nationwide three-digit telephone number for traveler information. This petition was formally supported by 17 state DOTs, 32 transit operators, and 23 Metropolitan Planning Organizations and local agencies. On July 21, 2000 the FCC designated 511 as the national traveler information number.

Simply put, 511 represents an abbreviated three-digit dialing code that is a short cut to a ten-digit telephone number for obtaining traveler information from a telephone. In petitioning the FCC, USDOT had to demonstrate the need and benefits for such a number. To that end, the USDOT identified the following:⁽²¹⁾

Further benefits are realized. 511 puts a "face" on ITS and transportation operations, while increasing attention on the potential for traveler information services. With 511, transportation agencies can offer easier access to information via telephone, and have the same number work in multiple places. It is not uncommon for traveler information numbers to change across jurisdictional boundaries, creating confusion among motorists.

In-Vehicle Displays

A video display terminal (VDT) mounted in the dashboard is another form for communicating with motorists in their vehicles. This is primarily a private sector industry, which has not been used widely for information distribution. These systems can be used to provide motorists with route guidance and navigational information in one of two different formats. One approach is to present the driver navigation and route guidance information in the form of maps or equivalent displays. With these systems, a global picture of the traffic network can be provided. Recommended routes can be highlighted on the video map display as well. In another approach, simple symbolic signals (e.g., arrows, text instructions, or a combination of both) guide the driver along a recommended route. Some prototype systems use a variety of displays depending upon whether or not the vehicle is in motion, the functions selected, and level of informational and navigational displays available.

In-vehicle VDTs offer a number of advantages over available technologies in providing information to motorists while driving. These include the following:

• Travel information is more readily accessible to the driver (providing continuous access to current position, routing, and navigational information).
• Computer-generated navigational maps and displays are logical extensions of traditional forms of providing drivers with route guidance and navigation information.

Information can be displayed in text, graphics, or both and tailored to the needs and desires of each motorist. There are also limitations to in-vehicle VDTs. These include the following:

• Drivers have to take their eyes off the roadway in order to receive the information.
• In-vehicle VDTs present the driver with complex maps and diagrams that may create a potential to overload the driver with too much information.
• VDTs may also add to the visual clutter already inside the vehicle.

As technology continues to improve, the Head-Up Display (HUD) has become another alternative to in-vehicle VDTs for presenting visual navigational and route guidance information to motorists. Although originally developed for the aviation industry, several automobile manufacturers are beginning to develop HUDs for presenting vehicle status and navigational information to drivers.

A wide variety of options for displaying information may be available using HUDs. Through both icons and alphanumeric text, navigation and route guidance information may be projected directly into the driver's field of view. This is expected to reduce the need for visual scanning between two information sources (the inside instrument panel and the outside environment) and the associated visual accommodation time.

Subscription Services

A number of private providers supply traveler information services on-demand as a subscription. Most notably, General Motors' (GM) OnStar is a 24 hours a day, 7 days a week motorist assistance system installed in the vehicle. It provides a wide range of services to the driver, including concierge service, telephone service, remote unlocking of the car, and notification of air-bag deployment just to name a few.

Another feature OnStar provides is route guidance to motorists. Here, the motorist initiates a call from a button installed in the car, is connected to a live Onstar operator, and proceeds to ask for directions. The operator knows the vehicle's location through OnStar's automated vehicle location system and provides directions for the fastest route. OnStar currently uses a third-party wireless analog network and is moving to a digital technology, which will allow the service to be expanded to handheld devices as well. Presently, 53 current (2003) vehicle models are offered with OnStar, and GM intends to expand to 60 models by the end of 2003. Routing assistance is the most utilized service, and OnStar reports that it handles more than 220,000 routing calls per month.⁽²²⁾

Personal Data Assistants

Personal Data Assistants (PDAs) are the next higher level of sophistication in both off and on-roadway information dissemination technology. PDAs are computer products that have enough power to support applications such as time management and handwriting recognition. By adding radio frequency (RF) communications technology, PDAs allow users to interact directly with travel information systems. This interaction allows users to obtain route planning assistance, traffic information broadcasts, and other pertinent information. Through keypad entry, the user can log on to the information system, request pertinent information, and then log off. PDAs offer the user increased communication and information transmission/receiving power over alphanumeric pagers.

Plan Specifications

An en-route traveler information plan must be developed in concert with the traffic flow plan and traffic control plan. The success of any traffic management plan depends on disseminating correct information to motorists at the right time and location.

Items to be included in this plan include:

• Names of contact person(s) for each involved partner
• Protocols and methods to be utilized to coordinate
• Definition of each partner's responsibilities regarding control and information exchange

Detailed plans are necessary that identify the facilities and resources to be used. For instance, what permanent CMS or HAR are to be used and what holes exist in the information dissemination strategy? Where will portable devices be required? Traveler information plans must include planned message sets for equipment and technology used to disseminate en-route traveler information, including static signs, changeable message signs, highway advisory radio, and telephone information systems.

As in the desktop exercise and modeling analyses, various scenarios must be examined, and as a result, specific tactical strategies will be developed. Of particular importance in planned special event management is the creation of information messages for the various devices available to the manager. This includes changeable message sign messages, highway advisory radio messages, Internet and PDA messages. Each of these must be developed for various scenarios, including contingency ramp closures, full parking lots, and emergency situations. The traveler information plan may also specify protocol for disseminating traveler information via the media.