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Federal Highway Administration > Publications > Public Roads > Vol. 68 · No. 3 > Operational Solutions to Traffic Congestion

Nov/Dec 2004
Vol. 68 · No. 3

Publication Number: FHWA-HRT-05-002

Operational Solutions to Traffic Congestion

by Jeff Paniati

Making the most of the highways already in place is one strategy for relieving gridlock.

Congestion occurs during longer portions of the day and delays more travelers and goods than ever before," says The 2004 Urban Mobility Report published by the Texas Transportation Institute (TTI) in September 2004. The TTI report notes that the average annual delay per peak traveler has gone from 16 hours in 1982 to 46 hours in 2002, or nearly tripled in the last 20 years. This equates to more than an average by Jeff Paniati 40-hour work week per year spent in congestion during peak travel times.

FHWA is aggressively attacking congestion, such as this four-lane gridlock, using comprehensive strategies focusing on near-term results.
FHWA is aggressively attacking congestion, such as this four-lane gridlock, using comprehensive strategies focusing on near-term results.

In addition, the TTI report indicates other consequences from delay:

"Congestion costs are increasing. The total congestion 'invoice' for the 85 areas [studied] in 2002 was $63 billion, an increase from $61 billion in 2001. The 3.5 billion hours of delay and 5.7 billion gallons of fuel consumed due to congestion are only the elements that are easiest to estimate. The effect of uncertain or longer delivery times, missed meetings, business relocations, and other congestion results are not included."

Although the causes of congestion are many and varied, the U.S. Department of Transportation Highway Statistics indicates that, over the last 20 years or so, nearly twice as many miles are driven today—on a road system that has increased in size by only 5 percent. Such heavy demand, coupled with temporary reductions in capacity resulting from causes such as crashes and work zones, are making traveling increasingly costly and frustrating. The Federal Highway Administration (FHWA) has identified congestion as one of three priority areas, along with safety and environmental stewardship and streamlining, known as the agency's "vital few" priority areas.

Traffic congestion need not be the normal state of affairs. In addition to traditional efforts, an increased focus of FHWA is the development and promotion of transportation systems management and operations. Better management and operations will not replace the need to build new roads or add transit capacity where appropriate, but they make the most of the infrastructure already in place. Similar to keeping an existing car in peak operating condition rather than buying a new one, operational strategies can be less expensive and quicker to implement than infrastructure-building projects, and can be very effective in reducing congestion and stretching infrastructure performance.

Transportation systems management and operations strategies have two overarching requirements. First is the need for institutional change through the reorientation of operations agencies from construction to management of the transportation system, plus collaboration and cooperation by traditional and nontraditional players (such as public safety agencies) in the workings of the transportation system. The second change is the development and deployment of 21st-century technologies, otherwise known as intelligent transportation systems (ITS), to improve the capability of agencies to manage the transportation system and the ability of travelers and commercial carriers to make informed choices about when and how to travel. FHWA is committed to fostering these changes in a variety of areas—incident management, work zones, weather management systems, freight transportation, and traditional traffic operations—each of which is discussed in this issue of PUBLIC ROADS.

Overview of the Congestion Problem

As mentioned earlier, delays have substantially increased. Accordingly, the "rush hour" over the last 20 years has increased from an average of 3 to 4 hours to 6 to 8 hours.

Over the past 20 years, rush hour has increased from 3-4 hours to 6-8 hours per day, often leading to commutes in darkness as shown here.
Over the past 20 years, rush hour has increased from 3-4 hours to 6-8 hours per day, often leading to commutes in darkness as shown here.

It is no secret that large urban areas suffer the most from congestion. In the 2004 TTI report, the largest urban areas included those with more than 3 million people, who averaged 62 hours of annual delay per traveler during peak periods compared with 25 hours per person for urban areas between 500,000 and 1 million. But less well known is the fact that smaller urban areas now are suffering the same degree of congestion as the largest urban areas did in the early 1980s, and this trend will most likely continue if changes are not implemented. The TTI report cautions, "Major projects, programs, and funding efforts take 10 to 15 years to develop. In that time, congestion endured by travelers and businesses grew to those of the next largest population group. So in 10 years, medium-sized regions will have the traffic problems that large areas have now, if trends do not change."

Nor is congestion limited to cities. Although it is more sporadic, delay often occurs in rural areas and heavily traveled intercity corridors, such as I-95 on the East Coast. Particularly hard hit are the arteries around popular tourist destinations, such as beach and ski resorts, in peak season. National parks, like Yosemite and Acadia, have been battling the effects of traffic for some time now, with current visitor projections threatening a rural version of gridlock. Work zones, poor weather, and special events are all causes that can create major backups in rural areas just as they can in urban areas.

Congestion studies show that about half of traffic delay is nonrecurring, attributable to temporary disruptions of the transportation system like traffic incidents, work zones, poor weather, and special events. The other half is recurring congestion, delay that occurs in the same place at the same time day after day.

Pie chart shows reasons for congestion.  Twenty-five percent of congestion is due to incidents (crashes disabled vehicles).  Fifteen percent is due to weather.  Ten percent is due to work zones.  Five percent is due to poor signal timing.  Five percent is due to other recurring congestion.  And, five percent of congestion is due to other nonrecurring special events.
About half of traffic delay is nonrecurring, attributable to temporary disruptions such as traffic incidents, poor weather, work zones, and special events.

The reasons for the increase in driving are varied and complex. They include, among others, growth in the size of the population and workforce, growth in motor vehicle ownership and affordability of use, growth in commuting to work alone, lack of transit availability because of urban sprawl, and changing patterns of land use. The rush period has worsened to some extent as a result of the increasing prevalence of chaining nonwork trips, such as picking up children and grocery shopping, with the commute. This development in turn is partly the result of the increasing numbers of double-wage earners in the workforce and the relative ease with which extra trips can be made with the availability and use of automobiles for work trips. Although chaining trips together reduces overall vehicle miles traveled and is good for the environment and efficiency, when it occurs during peak periods, it tends to add to the congestion rather than diminish it.

Freight movements too have grown with rising incomes and because just-in-time logistical arrangements often require smaller but more frequent deliveries. Commercial truck travel has doubled over the past two decades, the same rate as highway travel as a whole, but remains a relatively small share of total vehicle miles traveled (about 7.5 percent). Like all vehicles in the traffic mix, trucks add to congestion and are affected by it. Their contribution to congestion is more dramatic in certain places-near intermodal terminals, on long inclines, and on two-lane roads, to name a few. And the trend is to move a larger share of goods by road. According to the Commodity Flow Survey conducted by the U.S. Department of Transportation and the U.S. Department of Commerce's U.S. Census Bureau, the truck share of freight ton-miles increased in the last 10 years from 36 percent to 41 percent.

For both passengers and freight, it is not only travel delay that matters but also the reliability of the system. Reliable travel times are critical to truckers who serve just-in-time manufacturing and distribution systems and carry other time-sensitive shipments. Reliability is an issue with travelers, because they are often forced to schedule extra time to reach their destinations whether they actually encounter congestion along the way or not. Just the threat of travel delay is enough to persuade people to make adjustments.

Strategies to Mitigate Congestion

FHWA is committed to a long-term, comprehensive, four-part approach to mitigating highway congestion. The first component is the proper maintenance of the current road and bridge system. Proper maintenance lengthens the life of an asset and is less costly and disruptive in the long run than major rebuilding. Moreover, proper maintenance usually will prevent the travel problems associated with poor pavement and bridge conditions, including potholes and weight restrictions.

Second, FHWA believes that new construction of roads, bridges, and nonhighway infrastructure should be considered where appropriate, particularly to relieve bottlenecks and to reduce conflicts between modes. The Alameda Corridor project in southern California, for instance, eliminated 200 highway-rail grade crossings, reducing delay for cars and trucks and speeding rail transportation.

Third, transportation policies must encourage an appropriate balance between different modes, with highways seen as an integral element of the transportation system as a whole. In some places, agencies might relieve highway congestion by developing alternatives such as public transportation. For the transportation of freight, alternatives may mean promoting the use of a rail option in certain corridors.

Fourth, transportation systems management and operations strategies must be used to maximize the capacity of the infrastructure already in place. More efficient operation of the highway network can be a successful approach to addressing congestion. The increased focus on operations has two interrelated elements: creating a new culture within the agencies responsible for managing and operating the transportation system and deploying new technology to help operators and travelers.

Highway Agency of the 21st Century—A Culture Shift

Historically, highway agencies have focused their attention on building and maintaining road infrastructure. Less attention has been paid to operating the road system to provide the highest level of service. With increasing road congestion, the expense and difficulty of building new facilities, and the need for safe and secure highways, this view has begun to change. The highway community is coming to recognize how operational strategies—including traffic control and enforcement, incident and emergency management, ice and snow removal, and the deployment of ITS technologies—can make a major difference in how a highway system performs.

The Federal Highway Administration believes that the transportation agency of the 21st century must make a culture shift to integrate management and operations into transportation solutions. The agency must be customer focused and performance driven, with a systems approach, realtime and proactive management, and around-the-clock operations. It will have six characteristics.

First, a transportation agency needs to understand who its customers are (residents, tourists, workers, businesses, freight companies) and their needs. The agency recognizes that travelers care about the quality and reliability of their trips from end-to-end, regardless of what agency or jurisdiction "owns" the roadway. Agencies need to obtain feedback from their customers and be responsive to their travel needs. They need to make sure that information about the performance of the transportation system is readily available, timely, and targeted to the needs of the customer.

Second, performance of the transportation system is the key metric. Today the U.S. transportation community largely measures performance by the condition of the physical system. Increasingly, operating performance measures such as reliability and delay are becoming the important determinants of how well the system is meeting the needs of customers.

Traffic congestion at the border crossing in Blaine, WA.
Traffic congestion at the border crossing in Blaine, WA.

Third, an agency concerned about improving operations requires a regional and integrated systems approach to managing the performance of the transportation network. A regional view transcends city, county, and State boundaries and system ownership. The result is more focus on the operation of the entire transportation system regardless of agency ownership. A systems approach also refers to the integration of technical systems such as intelligent transportation systems within and across agencies. The performance of the transportation system is largely determined by the ability of agencies to work cooperatively by sharing data and coordinating responsibility.

Fourth, a key to virtually every congestion mitigation strategy is real-time, or near real-time, information about what is happening on the roadway system, including information on weather, incidents, speed, volume, work zones, and the like. This information can be shared with motorists to help them make their own decisions about when, where, and how to travel, and the information can be shared with multiple agencies for faster coordination and more precise responses. Improved information is also an asset to the freight community. Information on the location of freight shipments helps carriers manage their fleets, helps manufacturers control their inventory systems, and provides advance information to Federal agencies concerned with trade facilitation and national security.

Fifth, when agencies focused primarily on building roads, it was largely accomplished during "typical" work hours—8 hours a day, 5 days a week. Managing the system, however, requires being on the job 24 hours a day, 7 days a week. Delay can happen any time, any place, and for many reasons. To be responsive to customers, successful operations agencies must develop the capability to conduct at least some functions around the clock.

Finally, highway agencies that are focused on operations are proactive in anticipating and managing planned and unplanned transportation events. Planning for special events—including signal-timing changes, signing, and traveler information—is routine. Monitoring weather forecasts allows for use of anti-icing tactics and quick broadcast of road closures and limitations. Planning for traffic impacts from work zones ensures minimizing of disruptions to travelers and businesses. And planning for highway incidents, natural disasters, and security-related emergencies reduces their effects and helps bring the system back to normal operation more quickly.

Technologies to Improve Transportation Operations

Institutionally reorienting agencies from a construction philosophy to management and operations of the transportation system is only part of the solution. Another dimension of improving highway operations is the development and deployment of 21st-century ITS technologies, which provide a way to collect and share information about system conditions and the actions needed to keep people and freight moving. Transportation operators employ the information to decide how to use transportation control devices like ramp meters and other resources such as deicing trucks or emergency responders. Additionally, the information can be shared with travelers in a variety of ways, by message sign, phone, and the Internet, to let them make their own decisions about when and how to travel.

The synergy between various technologies is increasing every year as they become ever more widely available. For instance, the transportation community is looking at how vehicles in the future might be equipped with in-vehicle navigation systems that are able to receive realtime traffic information.

Taken together, these technologies facilitate new ways of managing the transportation system to improve its operation. The technologies by themselves do not address the problem of congestion, but they improve the transportation community's ability to operate the system and travelers to make their own decisions about traveling. The technologies generally can be grouped into six types.

Information-Gathering Technologies. Surveillance and detection cameras, traffic sensors, vehicle probes, and infrastructure sensors collect information more thoroughly or more frequently than transportation professionals have been able to do in the past.

Information-Sharing Technologies. As personal portable technology matures, an ever-increasing array of devices is available to share travel information. Today, variable message signs, highway advisory radio, the 511 number, Web sites, and specialized warning systems (such as fog warnings) are stationary technologies used routinely to share information with travelers.

This variable message sign displays travel time.
This variable message sign displays travel time.

Control Technologies. Advanced traffic signal controls provide ways of remotely adjusting systems of signals to respond in real time to changing traffic demands. Other technologies that provide opportunities to control traffic in real time include lane control signals, ramp meters, transit signal priority, and variable speed limit signs.

Vehicle-Based Technologies. From complex crash avoidance technologies to in-vehicle guidance systems currently on the market, vehicle based technologies hold promise to improve safety dramatically and give travelers (including commercial drivers) meaningful information about travel conditions to help them avoid bottlenecks and other potentially disruptive situations.

Vehicle-to-Roadside-to-Home-Base Technologies. These technologies enable freight operators of commercial carriers to maintain contact via satellite systems and terrestrial-based systems with their fleets and the cargo they are moving. Vehicle-to roadside-to-home-base systems are expanding in use and experiencing lower per unit costs, and have the extra advantage of addressing security needs as well as productivity and safety needs.

Payment Technologies. Electronic toll tags and "smart" cards for transit and parking are seeing rapid deployment. These technologies add efficiency to payment operations and expedite traffic flow.

Focusing on Near-Term Results

As part of the program to reduce congestion, FHWA has identified a number of program areas that are designed to advance system operations. The articles in this issue of PUBLIC ROADS and the Office of Operations Web site at www.fhwa.dot.gov/operations contain more information on these program areas. FHWA's operations efforts are organized around six strategies:

  1. Reducing Nonrecurring Congestion
  2. Reducing Recurring Congestion
  3. Improving Day-to-Day Operations
  4. Building a Foundation for 21st- Century Systems Management and Operations
  5. Enhancing Freight Management and Operations
  6. Improving Emergency Transportation Management

Reducing Nonrecurring Congestion

This strategy involves the development and deployment of strategies designed to mitigate traffic congestion due to causes such as crashes, disabled vehicles, work zones, adverse weather events, and planned special events. These nonrecurring temporary disruptions take away the use of part of the roadway and cause about half of total congestion.

The three main causes of nonrecurring congestion are incidents ranging from a flat tire to an overturned hazardous material truck (25 percent of congestion), work zones (10 percent), and weather (15 percent). Nonrecurring events dramatically reduce the available capacity and reliability of the entire transportation system.

This is the type of congestion that surprises motorists. They plan for a trip of 20 minutes and experience a trip of 40 minutes. Travelers and shippers are sensitive to the unanticipated disruptions to tightly scheduled personal activities and manufacturing distribution procedures. Aggressive management of temporary disruptions, such as traffic incidents, work zones, weather, and planned special events (all four are FHWA program areas), can reduce impacts and return the system to full capacity.

Reducing Recurring Congestion

Roughly half of the congestion experienced by Americans happens virtually every day during peak travel periods. This recurring congestion results from there simply being more vehicles than roadways. The number of vehicles trying to use the highway system exceeds the available capacity. Reducing recurring congestion requires the development and implementation of new technologies and new approaches for arterial management, corridor traffic management, travel demand management, and freeway management—all FHWA program areas. Also necessary is convincing travelers to make their trips at less congested times, on different modes, on less congested routes, or through means such as telecommuting rather than traveling on the highway system.

Highway Emergency Local Patrol (HELP) truck personnel in New York State assist motorists and law enforcement, helping to reduce nonrecurring congestion from incidents.
Highway Emergency Local Patrol (HELP) truck personnel in New York State assist motorists and law enforcement, helping to reduce nonrecurring congestion from incidents.

Improving Day-to-Day Operations

Effective highway-based transportation consists of three component parts: building the infrastructure, preserving the infrastructure, and preserving the operating capacity by managing operations on a day-to-day basis. An integrated approach to managing the performance of the transportation network meets the end-to end travel needs of the customer. At its core, operations is the application of programs, technologies, and business processes that support the flow of vehicles, travelers, and goods on the existing transportation infrastructure. Many of these activities are not new to transportation professionals who operate their systems on a daily basis. The FHWA Office of Operation's efforts support activities to improve day-to-day operations through asset management, application of traffic control devices, and real-time traveler information, and FHWA's programs use traffic analysis tools to improve understanding of problems and possible solutions.

Building a Foundation For 21st-Century Systems Management and Operations

Building a strong institutional foundation of partnerships is fundamental to supporting 21st-century operations. Partnerships focus on convening a wide variety of stakeholders, including many that have not typically been involved before, such as law enforcement and other emergency agencies. Included under the institutional partnerships are activities that cross functional and jurisdictional boundaries, such as traffic incident management programs, real-time traveler information services, response to weather events, and emergency management. They all depend on collaboration, coordination, and communication to achieve optimum performance and thus truly benefit the traveling public.

For the FHWA programs—regional systems management and operations—to be effective, those directly responsible for operating the transportation system must agree on measures to assess performance, a concept for how the system should be operated on a regional basis, and ways to make changes to achieve desired improvements in operating performance.

Fundamental to building the foundation is measuring system performance. Performance measures, another FHWA program, provides the basic understanding of whether congestion, reliability, and other aspects of highway system performance are becoming better or worse. The program also develops guidance for State and local transportation agencies on meaningful measures of performance under a variety of operating conditions. A more complete understanding of both recurring and nonrecurring delay and the ability of operations strategies to reduce delay and improve reliability are needed to guide future investments in the highway system. The saying "what gets measured is what gets done" applies to improving the performance of the highway system.

National Transportation Operations Coalition

dialog to foster, promote, and guide transportation operations throughout the country. The National Transportation Operations Coalition (NTOC) is a formal partnership of more than 20 transportation associations that represent both transportation professionals and nontraditional stakeholders involved in transportation systems management and operations activities and decisionmaking at State, local, and regional levels. An evolution of the former National Dialogue on Transportation Operations, NTOC works in cooperation with FHWA to identify, promote, and implement activities that advance management and operations principles and strategies.

Current activities of NTOC are aimed at increasing the focus on managing for performance, advancing the state of the practice in transportation operations and communications, educating, and advocating the benefits of improved systems management and operations. Part of the NTOC outreach includes a new Internet resource that provides an extensive range of information on transportation management and operations and ITS. The Web address is www.ntoctalks.com . For more information on NTOC, contact Zia Burleigh, FHWA Office of Operations, 202-366-1896.

In addition, a series of operations Webcasts will be held on a monthly basis and will be open to the public and private sectors. The Webcasts will feature current trends, tools, and noteworthy practices. To register or for more information, go to http://talkingoperations.webex.com.

Enhancing Freight Management and Operations

The transportation system is not only about moving people but also about moving goods. The smooth flow of freight is important to our Nation's economy and to maintaining global connectivity. As demand for freight transportation grows, concerns intensify about congestion, safety, and security. Freight shippers and carriers are especially sensitive to travel delay, and increasingly, to unanticipated disruptions to tightly scheduled manufacturing production and distribution systems. FHWA's The Freight Story: A National Perspective on Enhancing Freight Transportation indicates that the estimated cost of congestion to shippers and carriers is $25 to $200 per hour, depending on the product being carried. Unanticipated disruptions may add significantly to these numbers. Ports and border crossings with their intense focus of activity and today's concern with security are especially vulnerable to delay and unanticipated disruptions.

A roving Motorist Assistance Patrol also helps reduce congestion by providing help in West Memphis, TN, and Arkansas, delivering fuel, changing tires, jumpstarting vehicles, arranging tows, extinguishing fires, and rendering first aid.
A roving Motorist Assistance Patrol also helps reduce congestion by providing help in West Memphis, TN, and Arkansas, delivering fuel, changing tires, jumpstarting vehicles, arranging tows, extinguishing fires, and rendering first aid.

Accordingly, FHWA's freight program focuses on promoting an efficient, safe, and secure intermodal freight transportation system. The agency conducts research and streamlines freight operations through freight analysis, freight size and weight policies, and intermodal freight technology. The FHWA freight professional development program assists transportation and planning professionals in developing the knowledge base and skills needed to do their jobs effectively to meet the challenges of tomorrow.

Improving Emergency Transportation Management

The surface transportation system is vital to the Nation's economy, defense, and quality of life. The need for ensuring the function and integrity of the U.S. surface transportation system became clear following the events of September 11, 2001. Effective transportation operational strategies both during and after an event (manmade or natural) are key to safe and continuous movement of people and goods during a national emergency. State and local transportation agencies play key roles in ensuring that the transportation network operates effectively in the event of an emergency.

Response begins the moment an event occurs, including assessment of the event and what it means to the transportation system. The response may involve determining not only how to move people and goods, but also military deployments. Throughout all daily activities, public safety and security must be considered by preparing for emergency transportation operations, which is another FHWA program.

Conclusion

Among the strategies that address congestion, reduce unexpected delays, and make the most of the Nation's existing investments, continued advancement of better transportation operations plays a critical role. Operating the system at its peak efficiency and maximizing the available capacity hinge on reshaping transportation agencies to be customer focused and performance driven, while using systems approaches and real-time management on a 24/7 basis. Working together—at the Federal, State, local, and association levels—transportation agencies can create a culture that embraces management and operations as an integral and essential part of delivering transportation services and reducing congestion. It is not a matter of "if," but a matter of "when." It will not happen overnight, and it will not happen through any single act. The transportation community can accelerate the solution to congestion by being more aggressive in championing the need for transportation systems management and operations, more aggressive in showing the benefits of management and operations, and more aggressive in the deployment and use of traffic engineering, transportation management, and traveler information tools.


Jeff Paniati is the FHWA associate administrator for operations and leads the national program to improve the management and operation of the highway system. He is responsible for FHWA's effort in the areas of congestion management, ITS deployment, traffic operations, emergency management, and freight management and operations. Paniati also is currently directing the $200 million annual Federal ITS program, providing strategic direction, management, and oversight for this program across the U.S. Department of Transportation. His experience includes more than 20 years with FHWA, primarily in operations, safety, and ITS, and he has bachelor's and master's degrees in civil engineering.

For more information, visit www.ops.fhwa.dot.gov.

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