Skip to main content

First national study of US travel time reliability

Texas Transportation Institute (TTI) has published the 2011 Congested Corridors Report, the first nationwide effort to identify reliability problems at specific stretches of US highway responsible for significant traffic congestion at different times and different days. Researchers noted that the corridors included in the report were identified by the data itself.
April 30, 2012 Read time: 2 mins
RSS2347 Texas Transportation Institute (TTI) has published the 2011 Congested Corridors Report, the first nationwide effort to identify reliability problems at specific stretches of US highway responsible for significant traffic congestion at different times and different days. Researchers noted that the corridors included in the report were identified by the data itself.

5367 INRIX, a leading provider of traffic data and analytics, originated the corridor approach, using 10 hours of congestion per week to define a starting point for a congested corridor. To be considered a “corridor,” according to the Inrix standard adopted for this report, congestion should impact a freeway segment at least three miles long.

“Until now, we’ve been able to measure average congestion levels,” says TTI research engineer Bill Eisele, “but congestion isn’t an ‘average’ problem. Commuters and truckers are understandably frustrated when they can’t count on a predictable trip time from day to day.”

The report describes congestion problems in 328 seriously congested corridors over a variety of times — all day, morning and evening peaks, midday, and weekends. Not only were these roads found to have more stop-and-go traffic than others, they were also much less predictable — “so, not only does it take longer, commuters and truckers have a difficult time knowing how much longer it will take each time they make the same trip” said co-author David Schrank.

The 328 corridors, while accounting for only six per cent of the nation’s total freeway lane-miles in the US and 10 per cent of the traffic, account for 36 per cent of the country’s urban freeway congestion.

As the first look at travel time reliability across the US, researchers believe that the report can be useful in determining where transportation system improvements will have the greatest impact.

Click here for a copy of the report.

For more information on companies in this article

Related Content

  • Connected Tech for Construction Continuity
    December 11, 2020
    No one could have predicted the situation we found ourselves in in 2020, with a global pandemic bringing the economy to its knees, projects delayed overnight, rapid restarts, remote management, and challenging labor dynamics.
  • Cutting road deaths around the world
    February 27, 2020
    A new funding source will help cut road deaths around the world.
  • Traffic management drives sustainability
    June 18, 2012
    New initiatives could boost transport sustainability – David Crawford writes. New roles are opening up for urban traffic management systems in helping city authorities to meet increasingly stringent governmental and supra-governmental air quality standards. European local authorities are typically tasked with both traffic management and pollution monitoring within their areas, making them well placed to draw on the latter to mitigate the impacts of the former.
  • TomTom survey shows congestion worsening in 200 global cities
    April 10, 2015
    A survey of more than 200 major global cities shows that commuters in Istanbul experience the worst overall traffic congestion. The average 30-minute drive in Istanbul takes more than an hour during evening rush hour, leading to an extra 125 hours wasted stuck in traffic every year, according to the latest Traffic Index Survey from Tom Tom. However, in Los Angeles, a 30 minute commute in the evening rush hour will take 54 minutes, adding an extra 92 hours annually.