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

  • Highways England opts for warm mix asphalt
    August 26, 2021
    The company in charge of maintaining England’s strategic highways, including motorways and main roads, is officially shifting its preference towards using warm mix asphalt. Highways England lays out the case for its decision.*
  • Study reveals Warsaw as Europe’s most congested city
    July 12, 2012
    Vehicle GPS provider TomTom is revealing details of a study into traffic congestion it had carried out across Europe. This quarterly Congestion Index involves studies of 31 major European cities with populations of over 800,000. According to the study, Poland’s capital Warsaw suffers the worst traffic congestion of any European city. For the UK, the Leeds-Bradford are has come out as the most congested area. Drivers in the Yorkshire conurbation spend an average 86hours/year stuck in traffic jams according t
  • Questions over effect of tough sentences for driving offenders
    June 17, 2014
    A UK academic claims that research shows higher prison sentences are unlikely to deter death by driving offences. University of Leicester professor Sally Kyd Cunningham suggests new laws from the UK Government could fail as a deterrent to crimes committed while driving. In the wake of the Government’s recent announcement of a comprehensive review of driving offences and penalties, an academic from the University of Leicester has argued that higher prison sentences could fail to act as a deterrent against de
  • SolarLite road studs help slash fatalities on one of Britian's most dangerous roads
    February 29, 2012
    More than 304 people in the UK are alive today or have avoided the prospect of a lifetime of special care because just 15 roads have had simple improvements put in place, according to this year's tracking survey by the Road Safety Foundation.