Traffic Congestion Factoids
- Nationwide congestion (439 cities nationwide) results in approximately 4.2 billion person-hours of delay every year.
- Based on the most recent data available (2007), according to the Texas Transportation Institute, congestion in 90 largest urban areas it studied added up to 3.6 billion hours of delay, or an annual delay per traveler of 41 hours.
- The Texas Transportation Institute estimates that incidents cause 53 percent of the delay in 90 urban areas in 2007, or about 1.9 billion hours of delay.
- According to the Texas Transportation Institute, congestion in the 90 urban areas it studied in 2007 cost over $76 billion or $871 per traveler in wasted time and extra fuel.
- Signal timing improvements in Chandler, Arizona have reduced AM peak-period delays by 30 percent and PM peak-period delays by 7 percent.
- In Kansas City, Missouri a signal timing effort along a 1 mile stretch of Bannister Road resulted in improved traffic flow, including an annual reduction in delay of 101,000 hours, saving 346,000 liters (91,000 gallons) of fuel.
- Installation of variable message signs and an adaptive signal control system in Fargo, North Dakota resulted in an 18 percent reduction in travel times and a 21 percent increase in vehicle speeds.
- Ramp metering in Minneapolis-St. Paul led to a 9 percent increase in freeway volume and a 14 percent increase in peak period throughput.
- A combination of ITS technologies in Detroit, Michigan—including advanced traveler information systems, highway advisory radio, ramp metering, and variable message signs—increased average vehicle speeds by 8.7 kilometers per hour (5.4 mph), decreased trip times by 4.6 minutes, and reduced commuter delay by 22 percent.
- Several field studies show that adaptive signal control systems can reduce peak period travel times by as much as 11 percent.
- Models estimate that traffic signal control systems can reduce fuel consumption by as much as 13 percent.
- Studies at traffic management centers demonstrate ramp metering systems reduce accidents by between 15 and 50 percent.
- In Pennsylvania, the I-95 Traffic and Incident Management System (TIMS) reduced highway incident closure time by 55 percent.
- A dispatch center in Erie, New York reported that notification of incidents involving vehicles equipped with automated collision notification took about 1 minute, whereas notification of other incidents could take anywhere from 3 to 46 minutes.
- The New Jersey Turnpike Authority reports that their EZ Pass system reduces toll station traffic delay by 85 percent.
- In New York, New York the Tappan Zee Bridge reports 1,000 vehicles per hour in their electronic toll collection lane and less than 500 in the manual collection lane.
- The Advanced Regional Traffic Interactive Management & Information System serving Cincinnati and Northern Kentucky estimates that use of traveler information reduced fatalities 3.2 percent.
- In Colorado, a downhill speed warning system on I-70 decreased truck accidents 13 percent and decreased runaway ramp usage by 24 percent in 2 years.
- Work zone surveillance and incident response at the "Big-I" Interchange in Albuquerque, New Mexico reduced average clearance time by 44 percent in the first year.
- In the Washington, DC region, a study estimates that commuters using traveler information could improve their on-time reliability by as much as 16 percent.
- Users of the Advanced Traveler Information Service in the Washington, DC region were able to reduce the frequency of early and late arrivals by 56 and 52 percent respectively.
- Between 1980 and 2007, lane-miles of highways increased 7 percent while vehicle miles of travel increased 98 percent.
- In 2003, over 62,800 kilometers (39,000 miles) of highways in the United States had peak period congestion, and of these, over 10,900 kilometers (6,800 miles) were in rural areas.
- Local travel per person grew from 2.9 to 4.1 one-way trips per day (about 40 percent) from 1977 to 2001. Distance traveled daily per person grew about 54 percent—from 42 kilometers (26 miles) to 65 kilometers (40 miles).
Updated: March 2009
