As traffic congestion continues to worsen, the time required for a given trip becomes more unpredictable, and researchers now have a way to measure that degree of unreliability, introduced for the first time as part of the annual Urban Mobility Report (UMR), published by the Texas A&M Transportation Institute (TTI).

The Planning Time Index (PTI), a measure of travel reliability, illustrates the amount of extra time needed to arrive on time for higher priority events, such as an airline departure, just-in-time shipments, medical appointments or especially important social commitments. If the PTI for a particular trip is 3.00, a traveler would allow 60 minutes for a trip that typically takes 20 minutes when few cars are on the road. Allowing for a PTI of 3.00 would ensure on-time arrival 19 out of 20 times.

PTIs on freeways vary widely across the nation, from 1.31 (about nine extra minutes for a trip that takes 30 minutes in light traffic) in Pensacola, Florida, to 5.72 (almost three hours for that same half-hour trip) in Washington, D.C., according to the study by TTI, a member of The Texas A&M University System.

“We all understand that trips take longer in rush hour, but for really important appointments, we have to allow increasingly more time to ensure an on-time arrival,” says Bill Eisele, a TTI researcher and report co-author. “As bad as traffic jams are, it’s even more frustrating that you can’t depend on traffic jams being consistent from day-to-day. This unreliable travel is costly for commuters and truck drivers moving goods.”

Rankings of the nation’s most congested cities vary slightly from year to year, and many of this year’s top 10 are repeat performers. Washington, D.C. tops the list, followed by Los Angeles, San Francisco-Oakland, New York-Newark and Boston. The second five include Houston, Atlanta, Chicago, Philadelphia and Seattle. The report provides a detailed illustration of traffic problems in a total of 498 U.S. urban areas.

In addition to PTI, the 2012 UMR also debuts an estimate of the additional carbon dioxide (CO₂) emissions attributed to traffic congestion: 56 billion pounds – about 380 pounds per auto commuter.

“Including CO₂ emissions into the UMR provides another dimension to the urban congestion problem,” says researcher and co-author David Schrank. “It points to the importance of implementing transportation improvements to reduce congestion.” The analysis of CO₂ was made possible by funding from the National Center for Freight and Infrastructure Research and Education (CFIRE).

Traffic congestion in U.S. cities has remained relatively stable in recent years and continues to underscore the link between traffic and the economy, according to the UMR. As the nation’s job picture has slowly improved, some congestion measures in 2011 were generally comparable to the year before.

Fuel wasted in congested traffic reached a total of 2.9 billion gallons – enough to fill the New Orleans Superdome four times. That’s the same as 2010, but short of the 3.2 billion gallons wasted in 2005. The Travel Time Index (the difference in time required for a rush hour commute compared to the same trip in non-congested conditions) remained steady at 1.18, still short of the 1.23 level in 2005.

The total financial cost of congestion in 2011 was $121 billion, up one billion dollars from the year before and translating to $818 per U.S. commuter. Of that total, about $27 billion worth was wasted time and diesel fuel from trucks moving goods on the system.

The methods and measures developed by TTI and used in the Urban Mobility Report have been successfully implemented for policy making and prioritizing congestion-mitigating projects,” says report co-author and researcher Tim Lomax. “In light of the recent signing of the Moving Ahead for Progress in the 21st Century (MAP-21) Act, there is greater importance on using such measures to prioritize transportation improvement spending to get the highest investment return for the public.”

Researchers say that the most effective way to address traffic congestion varies from one urban area to another, but that in all cases, a multi-faceted approach should be used, relying on more efficient traffic management and public transportation in addition to new construction. Travel options such as flexible work hours and telecommuting should also be part of the mix.

The 2012 installment of the study includes 30 years of trend data with which TTI has measured and analyzed traffic congestion and its impact on life in urban America. The report is the third prepared in partnership with INRIX, a leading private-sector provider of travel time information for both commuters and shippers.

TTI, a member of The Texas A&M University System, seeks solutions to the problems and challenges facing all modes of transportation, as well as helping prepare students for transportation-related careers.

Since the early 1980s, the Texas Transportation Institute (TTI) has estimated congestion in hundreds of urban regions across the country. Published annually, the resulting Urban Mobility Report has been the most reliable source of congestion information available.

Although Institute researchers will continue publishing this report, the way they received their congestion data dramatically changed two years ago.

“Up until recently, congestion data were gathered from public sources,” Shawn Turner, head of TTI’s Mobility Division, explains. “Cities and state departments of transportation gathered that information themselves using sporadic traffic counters, a limited number of roadway sensors and a lot of estimations.”

Those methods seem primitive today compared to what is available from the private sector — real-time data thanks to global positioning system and Bluetooth® devices that are contained within many vehicles, cell phones and mobile devices. Traffic-monitoring companies receive data from the devices and can monitor actual speeds and travel times with ever-increasing accuracy on any major highway across the country — not just in urban areas. The data they collect are sold to auto manufacturers, fleet management companies, vehicle navigation firms and, now on a limited basis, government agencies.

TTI has just completed a report for the Federal Highway Administration (FHWA) that examines this new technology — the growing number of companies that collect the data, how the data are collected, the products used in collecting the data, who’s buying the data and how much the data cost, how the data are being used, and the legal issues surrounding use of private-sector data by the public sector. Private Sector Data for Performance Management will act as FHWA’s guide in assisting states and the federal government in using this information to manage/reduce congestion.

“FHWA really wanted to know everything it could about these new, private data sources,” Turner says. “It has been charged with knowing what the congestion problems are and where they are, and recommending where the money should go to help fix it.” Turner adds that the next transportation authorization bill will likely require a much more detailed level of congestion data for performance monitoring.

In addition to TTI, the University of Maryland and attorneys from the law firm of Nossaman, LLP, helped with the report.

“It’s clear that the technology is changing dramatically, and there are numerous questions about its use and application. The report is a starting point for FHWA,” Turner says. “It’s an exciting time because it’s entirely possible that a newer technology will emerge that will make this data collection method obsolete within a few years.”

This Issue

Making the Grade: Tomorrow’s Transportation System

Volume 48, Number 1
March 2012
Issue Overview

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• For More Information

“It’s clear that the technology is changing dramatically, and there are numerous questions about its use and application. The report is a starting point for FHWA. It’s an exciting time because it’s entirely possible that a newer technology will emerge that will make this data collection method obsolete within a few years.”
Shawn Turner,
head of TTI’s Mobility Division

For more information:

Shawn Turner
(979) 845-8829
shawn-turner@tamu.edu

]]> http://tti.tamu.edu/2012/03/01/fighting-congestion-with-technology-the-new-frontier-2/feed/ 0 http://tti.tamu.edu/2011/12/01/mobility-study/ http://tti.tamu.edu/2011/12/01/mobility-study/#comments Thu, 01 Dec 2011 18:40:18 +0000 Tobey http://tti.tamu.edu/?p=7498 Traffic Problems Tied to the Economy, Study Says

Even though it’s not cited along with monthly job statistics, traffic congestion is a sign of economic prosperity — and it’s also a vivid reminder of how it is possible to have too much of a good thing.

In the wake of several consecutive months of U.S. job growth, the Texas Transportation Institute’s (TTI’s) annual study on congestion suggests that too little progress is being made toward ensuring that the nation’s transportation system will be able to keep up with such growth in a revived economy.

TTI’s 2011 Urban Mobility Report illustrates congested conditions from 2010 on a number of national levels:

• The amount of delay endured by the average commuter was 34 hours, up from 14 hours in 1982.
• The cost of congestion is more than $100 billion, nearly $750 for every commuter in the United States.
• “Rush hour” is six hours of not rushing anywhere.
• Congestion is becoming a bigger problem outside of rush hour, with about 40 percent of the delay occurring in the midday and overnight hours, creating an increasingly serious problem for businesses that rely on efficient production and deliveries.

The typical commuter feels the impact of congestion in the form of stress and wasted time. But for manufacturers and shippers, that wasted time has a direct bottom-line impact. Efficiency suffers, prices go up, and employment weakens.

“If you invest in roads and transit, you get better service and access to more jobs,” says Senior Research Engineer Tim Lomax, one of the study’s authors. “Traffic management and demand management should be part of the mix, too. Generally speaking, mobility investments in congested areas have a high return rate.”

That connection was well illustrated in the 1960s, when the nation experienced its longest uninterrupted expansion in history, fueled in part by federal investment in the Interstate Highway System.

The Interstate Highway System grew rapidly from the late 1950s to the mid-1980s, and the U.S. economy grew along with it. Since then, growth in the interstate system has virtually stopped. “The only way U.S. companies have been able to keep their products competitive in the face of increasing traffic congestion and rising transportation costs is to squeeze every ounce of efficiency they can out of their supply chain,” says TTI Research Scientist David Ellis. “But there is a limit to efficiency, and without additional transportation capacity, transportation costs will increase significantly. The result will be higher prices and lost jobs.”

The Urban Mobility Report uses traffic volume data from the states and traffic speed data from INRIX, a leading private-sector provider of travel-time information. The combination produces a thorough and detailed illustration of traffic problems in 439 U.S. urban areas.

The most economical and effective congestion solutions involve traditional road building and transit use, combined with traffic management strategies such as signal coordination and rapid crash removal, and demand management strategies like telecommuting and flexible work hours. Land use and development patterns can play a positive role, as well.

“The solution mix may be different for each city, but the one thing they all share in common is urgency,” Lomax says. “If we want a strong economy, doing nothing is not a productive option.”

This Issue

What Next? Choosing Our Transportation Future

Volume 47, Number 4
December 2011
Issue Overview

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“The only way U.S. companies have been able to keep their products competitive in the face of increasing traffic congestion and rising transportation costs is to squeeze every ounce of efficiency they can out of their supply chain. But there is a limit to efficiency, and without additional transportation capacity, transportation costs will increase significantly. The result will be higher prices and lost jobs.”
David Ellis,
TTI research scientist

For more information:

Tim Lomax
(979) 845-9960
t-lomax@tamu.edu

]]> http://tti.tamu.edu/2011/12/01/mobility-study/feed/ 0 http://tti.tamu.edu/2009/09/01/urban-mobility-report-highlights-rare-congestion-decline/ http://tti.tamu.edu/2009/09/01/urban-mobility-report-highlights-rare-congestion-decline/#comments Tue, 01 Sep 2009 17:11:36 +0000 Chris Sasser http://tti.tamu.edu/?p=4263

IH-35 in Austin is one of the state’s heavily congested roadways.

Fuel prices that began rising at the end of 2007 helped ease the nation’s congestion slightly, according to the Texas Transportation Institute’s (TTI’s) Urban Mobility Report, released on July 8. The popular report found that, as a result, time wasted for the average commuter was cut by about one hour. Even so, most rush-hour travelers still spend nearly a full work week stuck in traffic each year.

Researchers Tim Lomax and David Schrank conduct the study, which has been analyzing the nation’s congestion since 1982. The Urban Mobility Report determines the annual delay per traveler and the amount and cost of fuel that’s wasted. In 2007, American commuters wasted 2.8 billion gallons of fuel for a total congestion cost of $87.2 billion, or $760 per traveler.
The nation’s 439 urban areas are studied — the top 90 locations are ranked in order of congestion, from Los Angeles, California, to Wichita, Kansas. Commuters wasted the most time in traffic in the following regions:

• Los Angeles – Long Beach – Santa Ana, California;
• Washington D.C. – Virginia – Maryland;
• Atlanta, Georgia;
• Houston, Texas;
• San Francisco – Oakland, California;
• Dallas – Fort Worth – Arlington, Texas;
• San Jose, California;
• Orlando, Florida;
• Detroit, Michigan; and
• San Diego, California.

“Chances are, most commuters did not notice the slight decrease in congestion from 2006 to 2007,” says Schrank. “However, we think the recession will have more of an impact on rush hour in some hard-hit areas.” Schrank and Lomax believe that overall congestion in 2008 and 2009 may also show a decline as a result of the economic downturn. However, they warn that any congestion relief as a result of the recession will end as the economy improves.
“Historically, when the economy rebounds after a downturn, so does the traffic problem,” Lomax points out. “But a lot of it may hinge on the price of gasoline at the time.”
The 2009 Urban Mobility Report was front-page news across the country. About 750 television and radio broadcasts and newspaper articles were aired or written on the report.
“Getting the word out to all the media is a major task,” says TTI Director of Communications Richard Cole.
Months before it is released, reporters from across the country inquire about the issue date of the Urban Mobility Report. For months following, the report is cited by reporters when their stories focus on traffic and transportation.

Sponsors for the 2009 Urban Mobility Report were the University Transportation Center for Mobility at Texas A&M University, the American Road & Transportation Builders Association – Transportation Development Foundation, the American Public Transportation Association and TTI.

This Issue

The Future of Rail in Texas

Volume 45, Number 3
September 2009
Issue Overview