Summary of ITS Best Management Practices and Technologies for the State of Ohio

Amy B. Massey, P.E., Kimley-Horn and Associates, Charlotte, North Carolina

George W. Saylor, P.E., Ohio Department of Transportation, Columbus, Ohio

Howard W. Wood, Ohio Department of Transportation, Columbus, Ohio

Brent Baur, Center for Transportation Policy Studies, UNC Charlotte, Charlotte, NC

Edd Hauser, P.E., PhD, Center for Transportation Policy Studies, UNC Charlotte

October 2001

1.0 Introduction

The Ohio Department of Transportation stands at an exciting crossroads in its development of intelligent transportation systems (ITS) to support highway operations and management. Many states have developed significant, integrated metropolitan transportation management systems. The purpose of this study was that in committing to the creation of an ITS program, ODOT executive management wanted to define and document the best practices and policies for ITS, as based on experience from other states and experts in the field. To carry out this work, the research focused on three primary questions:

· What were the causes of delay on Ohio's macro corridors?

· What was the profile of an ITS program to best address the causes of delay on these routes?

· What were the best practices and most cost-effective technologies to support Ohio’s ITS program?

The results of this policy study were significant, as it impacted and guided the planning of ITS deployment at a macro and regional level. Some tangible benefits from this study included: Specific functions provided by Ohio’s ITS program, technology recommendations that became policy and became incorporated into the design of metropolitan and rural ITS systems, opportunities for data sharing between different work units of the Dept., and ODOT organizational structure– staffing and budget– necessary to support ITS.

2.0 CONGESTION AND DELAY ON OHIO’S MACRO CORRIDORS

Ohio boasts three of the top 50 urban areas of the nation. Twenty-two of the twenty-five largest cities in the state are located in three major metropolitan areas (Figure 2), forming megalopolises of Cincinnati-Dayton, Central Ohio (Columbus), and Cleveland-Akron-Canton. Youngstown and Toledo form the other two distinct urban areas. Using macro-level tools, the Cincinnati, Cleveland, and Columbus metropolitan areas show congestion increasing over the past decade (Figure 3). Vehicle miles of travel (VMT) have increased by 20 percent in the greater Cleveland area, and by approximately 40 percent in the metropolitan areas of Cincinnati and Columbus. Figure 2 shows congestion indices by District, on both arterials and freeways. There are several factors that are causing Ohio’s congestion. Lack of funding for new construction, and increased truck traffic are two of the main factors.

These congestion trends (involving both automobiles and trucks) are severe and of concern to the Department, but implore more data and analysis. Specifically, how bad is recurrent congestion (congestion due to volume versus capacity) compared with incident congestion (congestion due to incidents such as weather, construction, or traffic accidents)? The question is far from academic, as its answer plays directly into the type and effectiveness of ITS programs appropriate for the state. In lieu of micro-level, on-going data collection efforts that would directly indicate the amount of congestion caused by incidents on a particular facility, a literature search was used to determine the magnitude of incident congestion in Ohio. Also, researchers used empirical data and theory from both Ohio and national experience. For the three major Ohio cities analyzed, TTI (Texas Transportation Institute) uses a freeway incident-to-recurrent congestion ratio of 1.3, resulting in the following estimates of annual person-hours of delay.

Recurring Incident Total Pct

Cincinnati 18,320 22,965 41,285 56%

Columbus 13,230 16,270 29,500 55%

Cleveland 16,490 20,370 36,860 55%

3.0 GENERAL ITS PROGRAM RECOMMENDATIONS

Recommended ITS Program Focus

Ohio’s ITS program for its eight largest urban areas should focus on incident management, which includes weather and construction- or maintenance-related operations. Crash response requires multi-agency and multi-jurisdictional efforts; therefore the level of technological sophistication and investment should be commensurate with the level of institutional cooperation in a give region.

Ohio’s rural ITS program should also focus on incidents: construction/maintenance operations and weather (snow and ice detection). This focus somewhat already exists through the Department’s maintenance of traffic policy, and through its strategic initiative to improve snow and ice detection.

Recommended ITS Program Functionality

With incident management as the thrust of the ITS program, the focus first turns to the functions (not specific technologies) that should be incorporated into urban, and in some cases rural, programs.

Non-technology Freeway Operations

For heavily traveled urban areas, freeway service patrols are one of the most effective, and cost-effective, incident management tools. At a minimum, Ohio’s three largest urban areas should have specially equipped vehicles outfitted to respond to incidents, and provide quick-clear and traffic control support. Close coordination with local police and fire agencies is critical to efficient operation of these services. This will necessitate working with emergency response agencies to use common radio frequencies.

Multi-agency Traffic Management

DOT, police, and fire agencies usually find

themselves with diverging and sometimes conflicting missions:

The DOT’s primary motivation is construction and optimizing traffic flow (though sometimes these activities conflict).
Police agencies focus on enforcement, and often as defacto first responders to incidents with some attendant traffic control duties. Their responsibilities for accident investigation can close down freeway lanes and substantially impact traffic flow.
Fire and emergency rescue agencies are primarily concerned with securing an accident scene for the safety of victims and agency personnel. Sometimes an inordinate number of travel lanes are closed for this purpose, with a corresponding impact on traffic.

The key to improving incident response and thus improving traffic flow is to improve the daily communication between the multiple agencies involved in the activity. The frequent interaction between agency personnel is best accomplished through the joint location of the agencies. In a collocated setting, there is transfusion of information and mission, improvement in understanding between agencies, and empathy for the others’ missions. As discussed below, agencies can collocate in a new dedicated structure, or partner in another agency’s facility.

Incident Detection

If agencies are collocated and dedicated to aggressive incident management, rapid detection and response to incidents becomes important to traffic management. Quick response minimizes the delay caused by incidents, which emphasizes the need for a good incident detection function. With collocation, incident notification should obviously be tied into a traffic management facility.

Incident location (regardless of detection) is often cited by fire personnel as a key deficiency of incident response. Put simply, many people are not familiar with directions and geography, which hinders their ability to accurately report the location of an incident. Reference markers help local agencies in accurately dispatching fire crews to incidents.

Traffic Monitoring

For ITS systems, it is helpful to monitor traffic speeds and sometimes volume. Speed data, provides a good indication of a facility’s operation. Monitoring is crucial if a system is designed to divert traffic to alternate routes; without information on these routes, traffic cannot be diverted.

Traffic Surveillance (video images)

ITS and freeway management systems create images of video display walls and NASA-style banks of video monitors. Video surveillance is a necessary component of urban traffic and incident management.

Traffic Control

The function of traffic control is to reduce demand at a given point of highway, such as during an incident. Both passive and aggressive options exist for traffic control. On the passive side, providing traveler information through the media can be effective and requires no investment by the public sector. On the aggressive side, ramp meters or gates that restrict or limit access are the best forms of traffic control.

It is recommended that traffic control be a part of urban operations systems. However, the enthusiasm for aggressive traffic control must be tempered by political reality. For example, ramp meters are almost universally disdained (Columbus is the only exception in Ohio). The problem is that the traffic control measures that are the most beneficial to the public at large are also the measures that are the most unpopular in a political sense.

Dissemination of Traveler Information

As with traffic control, traveler information can be provided through a variety of formats. The function of traveler information is separated to make a message signs, or highway advisory radio, to name a few. The function of traveler information is separated to make a distinction from traffic control; regardless of the technology deployed, there could by traffic control without information (eg., ramp meters). Traveler information usually provides a somewhat limited form of traffic control (eg., drivers might divert if warned of an incident).

Traveler information represents a higher level of service that can be offered by a transportation agency. For example, agencies could provide only incident management and still be providing great benefit to the traveling public.

Data Collection: Synergistic Opportunities

Besides data related to freeway traffic surveillance and control, there are other significant sources of data and data requirements for other sections of the Department:

· Freeway Operations- Responsible for both directly and indirectly guiding motorists in achieving less congested travel on Ohio’s freeways.

· Signal Operations- Responsible for traffic signal systems at freeway ramps and on rural, state/US-numbered routes.

· Maintenance Management- Responsible for the ongoing maintenance of interstate, state and US-numbered routes in non-incorporated areas, including snow and ice removal.

Technical Services- Responsible for traffic data collection, including count, classification, and weigh-in motion.

4.0 RECOMMENDED TECHNOLOGIES- A DETAILED ASSESSMENT

The recommended ITS program for Ohio was defined in terms of functionality that has a strong connection with the functions defined in the National ITS Architecture:

Non-technology freeway operations (service patrols, etc.)
Multi-agency traffic management (collocation of agencies)
Traffic Monitoring (speed, volume, classification)
Traffic Surveillance
Traffic Control (both passive and active methods)
Dissemination of traveler information (passive form of traffic control)
Data collection and analysis (combined functions for planning and operations)

It is recommended that collocation of police and fire agencies be integral to ITS investments in urban areas of Ohio. Optimally, police and fire dispatch offices should be collocated with traffic management. However, even the physical presence of a police and/or fire department representative in a regional traffic management center will provide significant benefits to all agencies involved in emergency response.

Based on the current trends toward market saturation, 9-1-1 cell calls routed to Public Service Answering Points (PSAP) are expected to continue to be the major reporting mechanism for incidents. Call takers determine if the emergency requires a police or fire response; if the call is emergency related, the call takers will record the information on a computer aided dispatch (CAD) system, allowing the emergency dispatcher for each jurisdiction to direct equipment and personnel to the scene.

Perhaps the basic function performed by a traffic management system, whether applied to freeways or major arterials, is vehicle detection. The ability to collect vehicle counts, measure detector occupancy, estimate vehicle speeds, and classify vehicles allows a TMC manager to evaluate the performance of the transportation network as well as monitor the system for irregular conditions and levels of congestion.

To perform a vehicle count, a detector needs only to register that a vehicle has entered its detection zone. To perform vehicle presence detection, a detector must be able to determine when a vehicle enters and exits its field of focus and how long it stays in the field. There are essentially four ways to determine speed: use magnetic probes in a trap configuration, use the Doppler frequency shift effect to determine the speed of vehicles when using active range-finding devices, assume an average vehicle length and take the time a detector field is occupied to determine speed, and use an object-tracking algorithm. There are also three methods of classification that are used: identify vehicles with long occupancies and attempt to segregate vehicles on the basis of vehicle length (usually limited to two or three times the length of an average automobile), use a range-finding device to scan a detector field and determine a vehicle profile based on length, height, and width dimensions of an automobile, and use video-based vehicle pattern matching.

Intrusive Vehicle Detector (buried in the pavement)

ODOT has made an important leap of faith into the world of real-time traffic operations. The creation of the Office of ITS Program Management, with staffing, provides an unprecedented central office level of commitment. However, institutional considerations serve as a cautionary tale for ITS program management, and the department has much work to do in aligning staffing and resources to support a real-time operations mission. As to positioning within the organization, it is entirely appropriate that the Office is now located in the Division of Planning, since that is the posture of the program at this time. In the future, however, it is recommended that the Office of ITS Program Management be melded into the Office of Traffic Engineering- a position more reflective of the program’s mission, and more in alignment with district counterparts.

Budget Considerations

Capital budgeting provisions for ITS projects reside with the Department’s Transportation Review and Advisory Committee, or TRAC. With no criteria, TRAC reviews ITS project requests and approves funding through very public and very formal deliberation processes. Although most ITS proposals to TRAC have been flawed, to date the TRAC has never approved a request for ITS funding. For ITS, the TRAC process is flawed because it doesn’t recognize operational improvements, instead being geared toward capital improvements projects. The only commonality between ITS and traditional highway and bridge projects is the cost. Optimally, the department should eliminate ITS projects from the TRAC process and set aside a separate, multi-year budget for capital funding of the systems. In lieu of such action, the Office of ITS Program Management should work with the TRAC to develop reasonable criteria for ranking and selection of ITS projects.

ITS operation and maintenance funding has not been a large problem for the department as a whole, but looms as an issue for widespread deployment. Current policy calls for ITS operation and maintenance funding to come out of district funding allocations, the same funds that are used for pavement maintenance, bridge maintenance and other operating activities. It is easily seen that funding ITS operations and maintenance takes away from bridge and pavement maintenance activities reduces district enthusiasm and support for ITS programs. This is especially true, given that ITS in not evenly deployed across the state at this time. To address equity issues, ODOT should centralize ITS operations and maintenance funding until ITS deployment becomes more widespread. While this would decrease the overall amount available to district maintenance allocations, it would reduce equity considerations during these crucial early years of ITS development.