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Publication Number: FHWA-HRT-06-095
Date: May 2006

508 Captions, Coordinated Freeway and Arterial Operations Handbook

508 Captions

Figure 1. Chart. Increase in congestion in the past 20 years in the largest U.S. cities.

Graphic shows that in 1982, intensity of congestion created a 13 percent average delay, duration of congestion was 4.5 hours per day, and the extent of congestion accounted for 33 percent of travel. In 2001, however, intensity had increased from 13 percent to 39 percent average delay, duration of congestion had increased from 4.5 hours to 7 hours per day, and congestion had increased from 33 percent of travel to 67 percent of travel.

Figure 2. Chart. Sources of traffic congestion.

Pie chart shows that bottlenecks account for 40 percent of congestion, traffic incidents account for 25 percent, work zones account for 10 percent, bad weather accounts for 15 percent, poor signal timing accounts for 5 percent, and special events account for 5 percent.

Figure 3. Chart. Relationship between regional and local functions.

The pyramid shows local functions, or functions localities already perform, on the bottom. Local/regional functions, or functions performed by local agencies with the region in mind is the title in the middle of the pyramid. Regional functions, which are functions that cannot be performed by localities alone but must be performed in conjunction with nonlocal agencies is titled at the top of the pyramid. The regional functions require collaboration and cooperation to be successful.

Figure 4. Chart. Elements of regional collaboration and coordination.

Diagram shows five linked elements of regional coordination: structure, process, products, resources, and performance.

Figure 5. Chart. Example of integrating regional and local processes.

Complex flowchart showing how regional and local processes are integrated in thePhoenix,Arizonametropolitan area. A number of organizations are grouped into three principals. The first group includes the Arizona DOT, Department of Public Safety (DPS), and Governor's Office of Highway Safety (GOHS). Within that group is the ADOT/DPS/GOHS Executive partnering team and the ADOT Transportation Review Committee (TRC). The next principal group is the Maricopa Association of Governments (MAG). Within that group are the MAG TRC and the MAG ITS Committee. The next principal group is the AZ Tech Executive Committee. Within this group are the AZ Tech Operations Committee, Advanced Traveler Information Services (ATIS), Incident Management, theEastValleyand West Valley Traffic Signal Timing Groups, and the ADOT TRC. Each element within the principal group is assigned a Regional Concept of Transportation Operations function; these functions range from interagency response plans to extraction of Computer Aided Design information toTransportationOperationsCenter/511.

Figure 6. Chart. The coordinated freeway and arterial operations framework.

Diagram shows the 11-step coordinated freeway and arterial operations framework. The framework is broken down into four phases: getting started, decisionmaking, implementation, and continuous improvement. The first phase, getting started, contains step 1, problem identification; step 2, institutional considerations; step 3, goals, objectives, and performance measures; and step 4, corridor concept of operations. The second phase is decisionmaking, and it contains step 5, corridor scenarios and operations strategies; step 6, evaluation and selection of strategies; and step 7, corridor implementation plan. Phase three is implementation, and it contains step 8, design and development; step 9, deployment; and step 10, operations and maintenance. The final phase, continuous improvement, contains step 11, continuous improvement.

Figure 7. Chart. Questions addressed by a concept of operations document.

Diagram shows the six questions that must be answered by a concept of operations document. The document must answer the question of who: who are the stakeholders involved in the system? Why: what does your organization lack that the system will provide? What: what are the known elements and high-level capabilities of the system? When: what is the time sequence of the activities that will be performed? Where: what are the physical and geographical locations of the system? How: what resources do we need to design and build the system?

Figure 8. Photo. Sample DMS message.

Photograph of a DMS sign with message reading 'use alternate route.'

Figure 9. Photo. Uncoordinated arterial signals can cause reduced effectiveness of ramp metering on freeways.

Photograph of traffic backed up at a metered freeway entrance ramp.

Figure 10. Photo. Dynamic lane assignment on an arterial.

Photograph of dynamic lane assignment signs over an arterial.

Figure 11. Photo. A freeway TMC collects and shares information from many sources.

Photograph of TMC staffer sitting at multiple computer terminals and monitoring information flow.

Figure 12. Chart. Example of development of corridor operations plans.

Complex flow chart showing an example of scenarios, activation matrices, corridor operations strategies, and operations plans. Scenario 1 is an incident on I-5 northbound between mileposts 50 and 60. The activation matrix shows 3 criteria, including one lane closed, two lanes closed, and full closure. For each criteria listed, there is a scenario for off-peak timing and a scenario that includes both a.m. and p.m. peak timing.

From the activation matrix, an arrow flows to a box labeled corridor operation strategies. Within this box are four categories: DMS messaging, signal timing, shared information, and lane assignments. Under each category is a list of strategic plans. Under DMS messaging are plans DMS-1 through DMS-3, with activities ranging from freeway DMS messages to DMS active route guidance. Under signal timing are plans ST-1 through ST-3, with activities ranging from standard timing plan to heavy diversion plan. Under shared information, strategy options range from plan SI-1, standard procedure to SI-3, TMC operator controls city signals. Under lane assignments are plans LA-1 through LA-3, with options ranging from no changes through temporarily close key on-ramps.

From the corridor operations strategies box, an arrow flows down into a box labeled operations plans. Here, there are two rows: scenarios and plans. For each scenario 1A through 1F, there is an associated list of operations plans. For example, under scenario 1A (one lane closed, off-peak timing) are Plans DMS-1 (freeway DMS messages), ST-1 (standard timing plan), SI-1 (standard procedure), and LA-1 (no changes).

Figure 13. Chart. Example of development of corridor operations procedures.

Flow chart showing a box with operations plans linked to a box with operations procedures. The operations plans box shows a list of scenarios across the top with the corresponding plans below each scenario. Plan 1B lists plans DMS-2, ST-2, SI-2 and LA-1. An arrow links plan 1B to the operations procedures box, where scenario 1B is expanded. Here, the action steps for plan 1B are listed and the responsibility for each action assigned.

The first four action steps are to verify field conditions match scenario, begin typical incident management plans, phone city engineer of conditions, and implement DMS messages. These are all the responsibility of the State TMC operator. Step 5 is to implement the signal timing plan; this is the responsibility of the city signal engineer. Step 6 is to monitor field conditions and check to see if a different scenario needs is activated; this is the responsibility of the State TMC operator and the city signal engineer. Finally, step 7 is to deactivate the plans when warranted; this is also the responsibility of the State TMC operator and city signal engineer.

Figure 14. Chart. Example of identifying field equipment responsibilities.

Snapshot of a table showing equipment onBarbur Boulevard. and Interstate 5. Table is reproduced.

The chart indicates who owns, maintains, controls and shares data/video onBarbur Boulevard. This can be compared with who owns, maintains, controls, and shares data/video on Interstate 5. The two agencies being compared are the city ofPortlandand the Oregon DOT. The five types of field equipment inventoried are CCTV, variable message sign, changeable message sign, ramp meters, vehicle detectors, traffic signals, and not applicable. At a glance, the user can see which pieces of equipment are managed by which agency. Check marks, or indicators of primary control, and secondary control are noted.

Figure 15. Photo. Traffic signal maintenance crew at work.

Photo of maintenance crew working on traffic signal. The maintenance truck is parked in one of the lanes of the intersection with crew in a cherry picker working on the traffic light overhead.

Figure 16. Chart. Example of operations plans and procedures for incident management scenarios.

Complex flow chart showing an example of scenarios, activation matrices, corridor operations strategies, operations plans, and operations procedures. Scenario 1 is heavy congestion on I-5 northbound between mileposts 50 and 60. The activation matrix shows 3 criteria , including right lane stopped, right and center lanes stopped, and all traffic stopped. For each criteria listed, there is a scenario for off-peak timing and a second scenario for both a.m. and p.m. peak timing.

From the activation matrix, an arrow flows to a box labeled corridor operation strategies. Within this box are four categories: DMS messaging, signal timing, shared information, and lane assignments. Under each category is a list of strategic plans. Under DMS messaging are plans DMS-1 through DMS-3, with activities ranging from freeway DMS messages to DMS active route guidance. Under signal timing are plans ST-1 through ST-3, with activities ranging from standard timing plan to heavy diversion plan. Under shared information, strategy options range from plan SI-1, standard procedure to SI-3, TMC operator controls city signals. Under lane assignments are plans LA-1 through LA-3, with options ranging from no changes through temporarily close key on-ramps.

From the corridor operations strategies box, an arrow flows down into a box labeled operations plans. Here, there are two rows: scenarios and plans. For each scenario 1A through 1F, there is an associated list of preset operations plans. For example, under scenario 1A (right lane stopped, off-peak timing) are Plans DMS-1 (freeway DMS messages), ST-1 (standard timing plan), SI-1 (standard procedure), and LA-1 (no changes). An arrow flows from this box to a box listing both designated operations plans and procedures. This box shows that for each plan that is implemented, there is an agency or entity responsible for a previously determined specific action step.

Figure 17. Graph. Integration of planned special event management phases.

The five phases of planned special event management are cyclical, beginning with Strategic Planning, then Event Operations Planning, then Training and Implementation, then Day-of-Event Activities, and ending with Post-Event Activities, which flows back to Strategic Planning.

Strategic Planning Products include: interagency coordination, policies and regulations, and infrastructure deployment.

Event Operations Planning Products: feasibility study flows to traffic management plan and travel demand management, traffic management plan flows to travel demand management, travel demand management flows to traffic management plan.

Implementation activities: implementation plan flows to review and testing and personnel training, review and testing flows to implementation plan.

Day-of-Event Activities: traffic monitoring flows to traffic management.

Post-event activities: participant evaluation and post-event debriefing flow to post-event report.

Figure 18. Chart. Stakeholders who may be involved in planned special events.

Diagram shows categories of special events stakeholders who should be involved in planning special events. The list includes representatives from law enforcement, including state police, county police/sheriff, and local police; the media, including television/radio and traffic advisory service; transportation agencies, including State DOT, county/local DPW, planning department and transit agencies; fire and EMS; the public, including both businesses and residents; government agencies, including the office of special events, department of permits, and emergency management agency; regional coalitions, such as metropolitan planning organizations and regional operating organizations; private industry, including transportation consultants, traffic control vendors, and ITS vendors; elected officials such as the mayor or city manager and city aldermen; and the event organizer.

Figure 19. Chart. Traveler interface with technology systems.

Flow chart shows how travelers can use personal computers to link into arterial information dissemination systems and freeway traffic control systems. Chart also shows how freeway and arterial systems are integrated together through shared information dissemination and data collection systems.

Figure 20. Drawing. Map of project area (black arrow shows the forward direction of diversion route).

Map of project area.

Figure 21. Chart. Off-peak strategy alternatives.

Graphic shows three interconnected columns of information: time of day, timing plan alternatives, and volume level. At the off-peak time of day, timing plan alternatives may include a field peak timing plan, an optimized off-peak timing plan without geometric change, and an optimized off-peak timing plan with geometric change. For each of these timing plans, plans can be broken out by volume level: plus 10 percent of critical volume, critical volume, and negative 10 percent of critical volume. Critical volume is the critical intersection's critical movement's demand at the volume to capacity ratio of 0.95.

Figure 22. Chart. Peak strategy alternatives.

Graphic shows three interconnected columns of information: time of day, timing plan alternatives, and volume level. At the peak period, timing plan alternatives may include a field peak timing plan, an optimized peak timing plan without geometric change, and an optimized peak timing plan with geometric change. For each of these timing plans, plans can be broken out by volume level: field peak timing plan is related to critical volume and the two remaining alternatives point to critical volume or plus 10 percent of critical volume. Critical volume is the critical intersection's critical movement's demand at the volume to capacity ratio of 0.95.

Figure 23. Chart. A major urban area situated along a navigable river with multiple east west bridge crossings.

Simple graphic showing two hypothetical cities:East Bend City in the Red State and West Bend City in the Blue State. The States and cities are separated by a river with three bridge crossings. These two cities create a major urban area and serve as a backdrop for the following examples.

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