Managing Congestion with Integrated Corridor Management

In “The 2007 Urban Mobility Report,” the Texas Transportation Institute calculates that in 2005 Americans who commuted during peak hours spent an average of 38 hours per year — beyond their normal commutes — in gridlock. Furthermore, the U.S. Transportation Secretary has called congestion one of the greatest threats to the nation’s economy, noting that drivers annually waste more than four billion hours beyond their normal commutes and about three billion gallons of increasingly costly fuel in traffic jams. The greatest concentration of congestion often occurs along critical transportation corridors, which link residential areas, business centers, sports arenas and shopping areas. Travel demand on U.S. roadways is outpacing available capacity at such a fast rate that new road construction alone will not solve the growing problem.

One solution that the U.S. Department of Transportation (USDOT) is pursuing is the concept of integrated corridor management (ICM). The USDOT’s ICM initiative focuses on providing real-time traveler information, coordinated multimodal operations and the use of technology to reduce congestion. ICM optimizes the use of existing infrastructure and leverages underutilized capacity on the nation’s urban corridors. ICM institutional partners manage the transportation corridor as a system rather than the more traditional approach of managing transportation facilities within the corridor as individual assets.

As Shelley Row, director of the Research and Innovative Technology Administration’s (RITA) Intelligent Transportation Systems (ITS) Joint Program Office (JPO), notes, “Many cities have invested significant resources in an ITS infrastructure for highways, arterials and transit systems. It is time to leverage this investment and operate the system in a coordinated manner that encompasses technical, operational and institutional coordination.”

For the purposes of the USDOT’s ICM Initiative, a corridor is defined as a combination of discrete adjacent or related surface transportation networks (e.g., freeways, arterials, bus routes, passenger rail lines) that link the same major origins and destinations. It is defined operationally rather than geographically or organizationally. Many transportation corridors contain underutilized capacity in the form of parallel routes, the “non-peak direction” on freeways and arterials and transit services. Transportation assets are often independently managed and operated and traveler information is often incomplete, fragmented or not completely useful.

USDOT believes that ICM will result in a reduction in travel times, delays, fuel consumption, emissions and incidents, an increase in transit ridership, and an improvement in the reliability of travel times. The vision of the ICM Initiative is to help metropolitan areas realize improvements in the movement of people and goods through the integration and management of transportation corridors as a system. As part of its knowledge and technology transfer efforts, USDOT freely shares the knowledge gained through this initiative with transportation practitioners around the country to equip them to implement ICM in their corridors.

The USDOT ICM Initiative has the following objectives:

  1. Demonstrate how operations strategies and ITS technologies can be used to manage the movement of people and goods in major transportation corridors efficiently and proactively through integration of the management of all transportation networks in a corridor.
  2. Develop a toolbox of operational policies, cross-network operational strategies, integration requirements and methods and analysis methodologies needed to implement effective ICM systems.
  3. Demonstrate how proven and emerging ITS technologies can be used to coordinate the operations between separate corridor networks to increase the effective use of the total transportation capacity of the corridor.

The USDOT’s ICM Initiative aims to enable corridor managers and operators across the country to optimize the use of existing infrastructure assets such as transit capacity along our nation’s urban corridors. The corridor-wide approach is designed to improve travel time reliability and predictability and to help manage congestion and empower travelers through better information and more choices. Row notes that the USDOT’s ICM Initiative, “provides a synergistic approach to the Congestion Initiative (see sidebar) as it offers the opportunity to truly advance transportation operations in a multimodal manner.” In a future ICM corridor, corridor managers could enable travelers to dynamically shift to alternate transportation options — even during a trip — in response to changing traffic conditions. For example, while driving in a corridor with ICM, a traveler could be informed in advance of congestion ahead on that route as well as alternative transportation options such as the location of a nearby transit facility, transit trip time from that location and parking availability information that would enable the traveler to shift to transit en route.

As part of this initiative, the USDOT is working with eight Pioneer Sites and having them each develop a concept of operations and system requirements for ICM operations in their respective corridors. The eight Pioneer Sites are: Dallas, Texas (U.S. Highway 75); Houston, Texas (I-10); Minneapolis, Minn., (I-394); Montgomery County, Md., (I-270); Oakland, Calif., (I-880); San Antonio, Texas (I-10); San Diego, Calif., (I-15); and Seattle, Wash., (I-5).

All eight Pioneer Sites are recognized leaders in the area of congestion management, and their efforts under this initiative will directly contribute to more efficient, faster moving and safer corridors for the future. All eight sites have committed to making the aggressive institutional changes required to implement ICM. The corridors of each Pioneer Site include configurations and characteristics that the USDOT believes represent many other corridors across the nation, and all possess infrastructure assets that can enable ICM. For example, all have transportation management centers (highway, transit and emergency management), some of which are co-located, and all have implemented real-time signal control on their arterials. Many have implemented advanced traveler information systems, such as 511, high-occupancy vehicle (HOV) lanes and value-pricing strategies, while others have advanced bus operations that include bus rapid transit (BRT).

The Pioneer Sites will develop multimodal ICM strategies that apply new institutional and operational approaches and advanced technologies to existing infrastructure to help to increase travel time reliability, manage congestion and empower travelers.

Transit agencies are a critical partner in any Integrated Corridor Management System (ICMS). Steve Rochon, senior staff engineer at the Maryland State Highway Administration, describes the biggest potential benefit of ICM as, “the enhanced integration of corridor operations and the respective highway, arterial, bus, rail and public safety systems that support these operations.” He notes, “Some of this integration is already in place; however, ICM will take it to another level. [In Maryland], integrating operations and systems across modes has the potential to greatly facilitate the movement of people and goods through the I–270 corridor [which terminates at the I–495 Capital Beltway around Washington, D.C.].”

The Four Phases of the USDOT’s ICM Initiative
The USDOT’s ICM Initiative will occur in four phases. These phases are designed to promote innovation in the development of new approaches for efficiently managing existing assets within a corridor. Ultimately, these four phases will help the USDOT and the Pioneer Sites to identify and advance promising ICM approaches that can serve as critical next steps in the nation’s efforts to reduce traffic congestion and to improve transit service.

Analysis, Modeling and Simulation
With so many potential ICM strategies, agencies are interested in analyzing the potential benefits of the various approaches to help them decide on specific ICM strategies to implement. Phase 2 of the ICM initiative involved selecting a test corridor to help generate insights on the expected benefits of implementing ICM. The USDOT selected the San Francisco Bay Area’s I–880 corridor to serve as the test corridor after a careful review of more than 20 candidate locations. This corridor is one of the main arteries in the San Francisco Bay Area, with 38 miles of freeway connecting Silicon Valley with the East Bay. It is a major freight and passenger throughway serving the Port of Oakland, Oakland International Airport and the Oakland Coliseum, as well as a concentration of residential, industrial and commercial properties. The USDOT also selected the San Francisco Bay Area’s I–880 corridor because of the wealth of available corridor data, multitude of transportation modes and facilities (freeways, arterials, HOV lanes, transit, etc.) and the transferability and applicability of results and methods to other corridors.

The Analysis, Modeling and Simulation (AMS) methodology used historical data from the test corridor to examine the potential implications of specific ICM strategies — such as adaptive ramp metering, traffic signal coordination, transit traveler information, highway traveler information, high-occupancy toll (HOT) lanes and combinations of these — under a variety of conditions, including medium and high travel demand, and with both a minor and a major incident along the corridor in each travel demand scenario. By using multiple ICM strategies, both separately and in combination, the team tested the AMS methodology comprehensively in terms of traveler response (route diversion, mode shift and temporal shift) and tested the interfaces for the flow of data among the modeling tools that were used. The test corridor experienced a 4 percent mode shift under high demand with a major incident when transit traveler information was provided (e.g., expected traffic delay, transit options, transit schedules, real-time parking availability).

ICM and Transit
Public transit is ideally suited to help increase capacity and improve passenger flow in congested transportation corridors. Transit, along with transit ITS technologies and strategies, will play a significant role in ICM, which is described by Pioneer Sites as “the next logical step for our nation’s corridors.” Transit often has underutilized capacity in corridors. Transit ITS technologies and strategies improve transit operations and service, making transit more appealing. Transit will serve two primary roles within ICM: balancing travel demand load during routine traffic conditions, such as recurring congestion and shifting the capacity burden from roads during major incidents, construction and special events to alternate modes and routes.

“The Federal Transit Administration [FTA] is committed to supporting integrated corridor management,” says Walter Kulyk, director of FTA’s Office of Mobility Innovation. “Transit can offer additional corridor capacity and provide an option for travelers during normal operations and during planned and unplanned events. Also, transit ITS technologies increase transit flexibility, efficiency and convenience for travelers.”

Balancing Travel Demand during Routine Traffic Conditions
Through various ITS strategies, such as transit signal priority (TSP) and BRT, transit can improve its travel times and trip time reliability, and thus make itself a more attractive and reliable option. Improved reliability of transit will encourage people to shift modes and thereby reduce the number of cars on the roads and improve overall traffic conditions.

TSP is an operational strategy that facilitates the movement of transit vehicles, usually buses and light rail vehicles, through traffic-signal controlled intersections. TSP can be implemented in a variety of ways; priority treatments include passive priority, early green (red truncation), green extension, actuated transit phase, phase insertion, phase rotation and adaptive/real-time control. BRT combines infrastructure and right-of-way design, new vehicle concepts and ITS transit technologies to provide high-quality rail transit while maintaining the flexibility of on-street bus operations. Houston, Minneapolis, Oakland and San Diego plan to use BRT within their corridors.

Shifting Demand from Roads during an Incident
In order to meet the unanticipated needs of travelers during a major incident and encourage mode shifting, corridor agencies must inform the public of the incident as well as advise travelers of their options, and transit agencies need to be able to accommodate the additional demand without much prior notice.

Corridor agencies must provide real-time, multimodal traveler information to the public to allow them to make informed trip decisions. A multimodal traveler information system would provide pre-trip and en-route information to travelers on roadways, transit (e.g., routes, schedules, fares) and parking (e.g., locations, number of parking spots, costs) via multiple outlets and media. Real-time information should be provided on traffic conditions (e.g., traffic speeds or travel times, road closure or construction locations and status, major incidents and delays, weather), transit conditions (e.g., closure or construction locations and status, major incidents and delays, real-time schedule status, projected transit vehicle arrival times), and parking availability. Web-based multimodal trip itinerary planning services that provide directions, travel times and costs to travelers for a trip from point A to point B for different roadway/transit route options could be included.

Some additional ITS strategies that can be used to make transit more attractive and accessible throughout corridors include integrated multimodal electronic payment; automated transit service coordination, such as connection protection; and HOV or HOT lanes. Integrated multimodal electronic payment systems allow customers to pay for tolls, transit and parking using a single electronic payment instrument (e.g., smart card) and a single customer account. They support different transit fare structures and allow transit agencies to change fares to help control demand during changing corridor conditions (e.g., lower fares during a freeway incident to provide an incentive for drivers to shift to transit). Integrated multimodal electronic payment systems make paying for transportation services more convenient by not requiring people to carry cash or exact change and allowing people to pay for services among multiple transportation systems and agencies using one medium. They expedite travel through toll lanes and parking lanes and reduce dwell times at transit stops. In addition, connection protection automates service coordination at designated transfer locations, making transit service more seamless and convenient, and helps to ensure that riders make their connections to less frequent transit service, such as commuter or feeder bus routes. HOV and HOT lane facilities provide near free-flow travel speeds and accommodate BRT operations, reducing travel times and improving travel time reliability and bus schedule adherence.

Focusing on the Customer: Transit Takes a Systems View
According to FTA Administrator James Simpson, the FTA is shifting its focus to reflect this need to manage the transportation as a system from the customers’ points of view. “Don’t think mode, think people,” he states. “I believe that we must stop thinking in terms of mode — no more highways versus transit or bus versus rail. Instead, we must think in terms of people and focus on our customers.”

In order to be successful in continuing this shift in focus to the customer, transit agencies must think about long-term solutions. Agencies must also commit to working proactively with their corridor partners to define and manage the corridor as an integrated system. “To accomplish the goals of ICM, all our partner agency representatives put away their badges, as we intend to operate our corridor in a true multimodal, integrated, efficient and safe fashion where the focus is on the transportation customer,” says Koorosh Olyai, assistant vice president for Mobility Programs Development at Dallas Area Rapid Transit (DART).
Simpson questions whether transit agencies will be able to manage a 5, 10 or even 15 percent increase in ridership and asserts that, in the short term, agencies may be able to add service or redeploy their existing efforts. In order to make this a sustainable reality, agencies need to do more. ICM is one potential solution. Through the use of various transit ITS technologies and strategies (such as automatic vehicle location/computer-aided dispatching decision support systems, automatic passenger counters, TSP and BRT) and the increased communication and cooperation with corridor partners that ICM requires, transit agencies may be better equipped to handle fluctuating capacity demands while increasing reliability and accessibility.

Next Steps
The USDOT is committed to equipping transportation managers and operators across the country to implement ICM in their corridors. The Pioneer Sites have developed their own Concepts of Operations, and are currently developing requirements documents for their ICM concepts. The USDOT expects to post the Pioneer Sites’ Concepts of Operations and requirements documents, as well as lessons learned from these activities — including the institutional changes needed to successfully implement ICM — to the ICM Knowledgebase ( in the summer 2008 timeframe. Early results from the analysis and modeling efforts, including the test corridor results, are expected to be made available in this timeframe. USDOT will also release practical AMS tools that corridor managers and operators can use and apply in their corridors through this initiative, along with lessons learned in this area as well. Furthermore, the USDOT will host panel discussions, workshops and Webinars over the next year to transfer knowledge to interested transportation practitioners.

The ICM Knowledgebase is a searchable, browseable, Web-based reference tool designed to provide transportation professionals with the knowledge and tools they need to successfully implement ICM in their corridors. The ICM Knowledgebase contains leading-edge knowledge developed through the USDOT’s ICM Initiative, such as the Pioneer Site Concepts of Operation and requirements documents, as well as lessons learned directly from the Pioneer Sites in the planning and implementation of ICM.

The highly usable ICM Knowledgebase was designed with input from multimodal stakeholders to help users intuitively and conveniently access the information they need. Users may search the Knowledgebase by keyword or browse its contents by a number of views, including type of resource (guidance, lessons learned, presentation, sample documents/templates, etc.), associated ICM life-cycle step, publication date of document or conference/event. The Knowledgebase also provides users with at-a-glance document abstracts; usage guidance, including product applicability to targeted audiences; and other information, including file size and number of pages, to help users to determine which documents may be most useful to them. Documents are being added regularly to the Knowledgebase as the ICM Initiative moves along.

The ICM Knowledgebase is part of an overall ICM Web site, available at Bookmark this site to stay informed about ICM developments including the Pioneer Sites’ progress in the development of innovative ICM strategies to manage congestion. For more information about the ICM Knowledgebase please visit

The ICM Newsletter is produced regularly to inform ICM stakeholders across the country about the USDOT ICM Initiative, including the latest knowledge and technology transfer materials that are available. The ICM newsletter was launched in June 2007. To view the newsletter online or sign up to receive it via email, please visit

Michael Baltes serves as the FTA ITS Program Manager. He is a member of two Transportation Research Board (TRB) committees and serves on the American Public Transportation Association’s (APTA) BRT Task Force.

Brian Cronin serves as the RITA ITS Joint Program Office Manager for the ICM program. He is the Congestion Program Coordinator for the ITS JPO and serves as technical representative for the Montgomery County, Md., and San Antonio, Texas, Pioneer Sites.

Steve Mortensen is a Senior ITS Engineer with the FTA Office of Research, Demonstration and Innovation. He is the technical representative for the Dallas, Texas, Oakland, Calif., and San Diego, Calif., Pioneer Sites.

Dale Thompson is a Transportation Research Specialist in the Federal Highway Administration’s (FHWA) Office of Operations. He is also the technical representative for the Houston, Texas, Minneapolis, Minn., and Seattle, Wash., Pioneer Sites.

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