226
Views
11
CrossRef citations to date
0
Altmetric
Original Articles

Traffic Speeds on Interstates and Freeways 10 Years After Repeal of National Maximum Speed Limit

&
Pages 119-124 | Received 16 Oct 2007, Accepted 03 Jan 2008, Published online: 08 Apr 2008
 

Abstract

Objectives. Essentially all published analyses of operational and safety outcomes related to enactment or repeal of the national maximum speed limit (NMSL) were based on data limited to the initial 1–3 years. The purpose of the present study was to collect and analyze longer term speed data.

Method. In 2006, traffic speeds were surveyed at 26 locations on urban and rural expressways in five states (California, Montana, Nevada, New Mexico, and Texas) where speeds had been measured in 1996, immediately after repeal of NMSL. Most speed limits were unchanged during the approximately 10-year period. However, Montana introduced a numeric 75 mph limit for passenger vehicles in place of a “reasonable and prudent” limit. In Texas, urban freeway speed limits for passenger vehicles were reduced 5 mph, and truck limits were increased 5 mph.

Results. On rural interstates without speed limit changes, travel speeds increased for both passenger vehicles and large trucks; the proportion of passenger vehicles exceeding 80 mph tripled. On rural interstates in Montana where speed limits were lowered for passenger vehicles, travel speeds decreased, even for large trucks whose speed limits had not changed. On urban freeways where speed limits did not change, travel speeds declined somewhat for both passenger vehicles and large trucks; during the study period there also were large increases in traffic volume and development of surrounding areas. On urban freeways in Texas where speed limits declined for passenger vehicles, travel speeds generally decreased, even for large trucks whose speed limits actually had increased.

Conclusions. The data suggest that where traffic volumes allow, travel speeds still are increasing 10 years after repeal of NMSL, and many drivers are speeding. The study also shows that speed increases can be curbed and even reversed when speed limits are lowered. Increased enforcement is needed to curb speed increases and the increased risk of serious crashes.

ACKNOWLEDGMENT

This work was supported by the Insurance Institute for Highway Safety.

Notes

∗No numeric limit.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 61.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 331.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.