Actual Versus Posted Speeds on Arizona Highways

Analysis of the traffic data collected at automatic traffic recorders maintained by the AzDOT Transportation Planning Division show that the incidence of speeding is extensive throughout the state and that it is on the increase when looking at data from the years 2000, 2001, and 2002. The three-year average percentages of vehicles exceeding the posted speed limits on 55, 65, and 75 mph roadways are 69.2, 53.9, and 46.2 percent, respectively. The data clearly show there is a significant problem that needs to be addressed. Some points to be considered are as follows: (1) The speeding problem is worse on high volume roadways, primarily on the functional class of roadway identified as “urban principal arterial – interstate.” (2) Speed data from ATR sites should be analyzed routinely to allow for targeted enforcement efforts to make the most of limited resources. Problem areas can be identified relative to ATR site, the time of day, day of the week, and time of year. (3) Since inappropriate posted limits can create problems, the limits should be reviewed periodically as traffic and land use changes affect the roadway. Adjustments to raise or lower the speed limit should be made to fit the new conditions. The statistics in this paper support the notion that not enough is being done to reduce speeding on Arizona roadways. When analyzing traffic data it is not clear whether speed limits are set too low or enforcement efforts are not adequate. A more concerted effort to address this problem is clearly warranted.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Semmens, John
  • Skszek, Sherry
• Conference:
  • Transportation Research Board 85th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2006-1-22 to 2006-1-26
• Date: 2006

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; References; Tables;
• Pagination: 119
• Monograph Title: TRB 85th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

• TRT Terms: Automatic vehicle monitoring; Detection and identification; High volume roads; Land use; Speed detectors; Speed limits; Speeding; Traffic data
• Uncontrolled Terms: Automatic traffic recorders; Traffic patterns
• Geographic Terms: Arizona
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 01023196
• Record Type: Publication
• Report/Paper Numbers: 06-0075
• Files: TRIS, TRB
• Created Date: Mar 3 2006 10:15AM