Economic Analysis of Speed Limit Policy Impacts

Speed management has been a longstanding concern of transportation agencies. Recently, nationwide speed limit policy modifications have resulted in a general upward trend in many states, including newly proposed legislation to raise the maximum speed limits on freeways and high speed rural non-freeways in Michigan. This legislation also proposed to eliminate the freeway differential speed limit between passenger vehicles and trucks/buses. Research was performed to assess the tangible economic impacts associated with the speed limit policy alternatives under consideration in Michigan. The economic assessment included systemwide estimation of the agency and user costs and benefits for each policy alternative, including those related to necessary infrastructure modifications, increased fuel consumption, reduced travel times, and fatal crashes. Calculation of the benefit/cost ratios indicated that none of the proposed speed limit increase scenarios present a favorable economic condition compared to the current policy. This was especially true for the proposed policy scenarios that involved an increase in the maximum speed limit, opposed to only increasing the truck/bus speed limits, due in large part to the substantial infrastructure costs associated with geometric modifications that will ultimately be necessary for compliance with state and federal design speed requirements. Such costs will be especially severe for non-freeways and select urban freeways in dense urban areas, which are currently posted at 55 mph. Consequently, speed limit increases on high speed roadways should only be considered for sections of roadway where design speed compliance is largely maintained after the increase to avoid costly geometric improvements.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ABE20 Transportation Economics.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Gates, Timothy J
  • Savolainen, Peter T
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: References; Tables;
• Pagination: 17p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Alternatives analysis; Benefit cost analysis; Economic impacts; Freeways; Geometric design; Infrastructure; Speed limits
• Geographic Terms: Michigan
• Subject Areas: Economics; Highways; Operations and Traffic Management; Policy; I10: Economics and Administration; I73: Traffic Control;

Filing Info

• Accession Number: 01554330
• Record Type: Publication
• Report/Paper Numbers: 15-3593
• Files: TRIS, TRB, ATRI
• Created Date: Feb 26 2015 9:49AM