Work Zone Mobility and Safety Program
Photo collage: temporary lane closure, road marking installation, cone with mounted warning light, and drum separated work zones.
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Facts and Statistics – Work Zone Mobility

Work zone activity occurs on roads that are often already congested.

  • 25 percent of lane-miles among the major road system were congested in 2014. This percentage is lower than has been reported in previous years, due to changes in how congestion is now being measured.
  • Yearly peak period delay for the average commuter was 42 hours in 2014, up from 18 hours in 1982. (2015 Urban Mobility Scorecard (PDF 4.7MB)
  • Americans lose 6.9 billion hours and 3.1 billion gallons of fuel every year sitting in traffic jams.
  • Approximately 40 percent of total delay occurs in the midday and overnight (outside of the peak hours of 6-10 a.m. and 3-7 p.m.), and so is predominantly attributable to sources of non-recurring congestion including incidents, weather, work zones, and special events.

Work zones account for a significant portion of "non recurring" congestion.

  • Nearly 24 percent of non-recurring freeway delay, equivalent to about 888 million hours in 2014, is typically attributed to work zones.
  • Work zones are estimated to constitute about 10% of overall congestion which translates into an estimated annual fuel loss of over 310 million gallons in 2014.

Timing and Impact of Lane Closures from Work Zones

(2001: A Snapshot of Peak Summer Work Zone Activity Reported on State Road Closure and Construction Web sites combined with unpublished data from 2002-03)

  • About one-third of work zones with lane closures occurred primarily at night.
  • The most likely hours of the day for a lane closure were 9-11 AM (two-thirds of all work zones), while the least likely was 6-7 PM (one quarter of work zones).
  • Greater than 60 million vehicles per hour per day of capacity were estimated to be lost due to work zones over a two week period during the peak summer roadwork season in 2001.
  • The loss of nationwide capacity on the NHS each day during the summer construction season is about 180 million vehicles. Losses in the peak hour were equivalent to the carrying capacity of more than 5,000 miles in one direction on a six-lane freeway.

Work Zone Mobility Performance Measurement

Some agencies are beginning to measure how work zones in their jurisdiction are actually affecting mobility. For additional information regarding work zone mobility monitoring and measurement, see these links for more details:

Sources of Information

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