Putting travelers in the know: providing motorists with real-time traveler information is a key way that road managers can help motorists deal with the growing traffic congestion on the nation's highways

Public Roads, Nov-Dec, 2004 by Brandy Meehan, Bob Rupert

According to the Texas Transportation Institute (TTI), unexpected congestion has a significant impact on motorists' attitudes. In its 2001 report, Traffic Congestion and Travel Reliability: How Bad Is the Situation and What Is Being Done About It?, the institute found that travelers want to know what to expect and almost always respond positively to accurate traveler information.

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To generate real-time traveler information, traffic managers use intelligent transportation system (ITS) technologies to collect data on traffic volumes, queue lengths, speeds, and travel times. By combining these data with information gathered from highway service patrols and public safety response centers, managers can help ensure that motorists receive the most up-to-date, accurate, and high-quality information.

"Delivering traveler information in real time has the potential to improve the driving experience, both by decreasing stress levels for motorists and improving the reliability of travel times," says Associate Administrator of Operations Jeff Paniati at the Federal Highway Administration (FHWA). "Many public agencies and private companies count on real-time traveler information to improve system performance, ensure customer satisfaction, and help make businesses profitable."

Access to up-to-the-minute information about traffic incidents, travel times along major corridors, and route-specific weather conditions can help motorists make more informed decisions and have more control over their trips. Public agencies and private companies have been providing traveler information for more than 20 years, but new ITS infrastructure and emerging technologies promise to broaden the amount and quality of real-time information available in the future.

Reducing Stress

Knowing how long a challenging situation may last often helps people cope with the situation, even if their options are limited and the situation is not expected to improve quickly. When the power goes off, for example, simply knowing what caused the outage and when the problem might be fixed can put peoples' minds at ease. Traveler information can work the same way.

Route-specific, real-time traveler information provides drivers with choices that could improve their travel times or at least provide a level of confidence in understanding the cause of the problem. Even if a traffic delay is unavoidable, motorists will know the severity of the situation and when it is likely to improve.

In most major metropolitan areas, commuting to work is becoming increasingly time-consuming and stressful for drivers. The 2004 Urban Mobility Report published by TTI in September 2004 cites 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. Total delay over the same period went from 0.7 billion hours to 3.5 billion hours.

In 2000, a marketing survey of 800 Minnesota households found that 66 percent of respondents thought the stress associated with traffic congestion was more difficult to deal with than a longer commute time. "People are experiencing more stress due to increased congestion and they want something done," said former Minnesota Department of Transportation (DOT) Commissioner Elwyn Tinklenberg in response to the survey.

Many transportation professionals agree that real-time traveler information can decrease the amount of stress associated with driving. A survey of Seattle-area users of the Washington State DOT traveler information Web site found that nearly three-quarters of respondents agreed that access to the site had reduced the stress of traveling in the metropolitan area. FHWA is sponsoring further research into the contribution of traveler information to reducing drivers' stress. Specifically, the research will model driver behavior to determine the value of traveler information in reducing stress. The results will be published in 2005.

Mobility Benefits

In addition to relieving stress, real-time traveler information also can produce measurable mobility benefits. According to FHWA research, more than 68,400 kilometers (42,500 miles) of highways in the United States experienced congestion in 2000. When traffic volume is near or exceeds capacity, the slightest incident can cause major backups and unexpected delays.

Travelers are accustomed to certain levels of congestion during their weekday commutes, but variability in travel times can cause inefficiencies for commuters, business travelers, and commercial vehicle operators. Without accurate and timely travel information, commercial vehicle operators risk falling behind schedule, and commuters have to build in extra travel time to ensure that they arrive at their destinations on time. This leads to wasted time and frustration.

A recent U.S. Department of Transportation (USDOT) study of advanced traveler information systems (ATIS) found that the potential benefits of traveler information are greatest in cities with the most day-to-day network variability. The study also found that in all cases, pretrip traveler information was highly beneficial. Motorists using traveler information in Cincinnati, OH, for example, reduced late arrivals by 37 percent, early arrivals by 91 percent, and early and late schedule delays by 30 and 69 percent, respectively. Just-in-time arrivals increased by 17 percent.