Effects of Raising and Lowering Speed Limits
(Part of the Reasonable Drivers Unanimous site)
Final Report
Report No. FHWA-RD-92-084 October 1992
U.S. Department of Transportation Research, Development, and Technology
Federal Highway Administration Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, Virginia 22101-2296
- Type of report and dates covered:
- Final, October 1985 - June 1992
- Abstract:
- The objectives of this research was to determine the effects of
raising and lowering posted speed limits on driver behavior and
accidents for non-limited access rural and urban highways. Speed
and accident data were collected in 22 States at 100 sites before
and after speed limits were altered. Before and after data were
also collected simultaneously at comparison sites where speed
limits were not changed to control for the time trends. Repeated
measurements were made at 14 sites to examine short - and long-term
effects of speed limit changes.
The results of the study indicated that lowering posted speed
limits by as much as 20 mi/h (32 km/h), or raising speed limits
by as much as 15 mi/h (24 km/h) had little effect on motorist'
speed. The majority of motorist did not drive 5 mi/h (8 km/h)
above the posted speed limits when speed limits were raised, nor
did they reduce their speed by 5 or 10 mi/h (8 or 16 km/h) when
speed limits are lowered. Data collected at the study sites indicated
that the majority of speed limits are posed below the average
speed of traffic. Lowering speed limits below the 50th percentile
does not reduce accidents, but does significantly increase driver
violations of the speed limit. Conversely, raising the posted
speed limits did not increase speeds or accidents.
- Performing Organization Name and Address:
- Martin R. Parker & Associates, Inc.
38549 Laurenwood Drive
Wayne, Michigan 48184-1073
- Sponsoring Agency Name and Address:
- Office of Safety and Traffic Operations R&D
Federal Highway Administration
6300 Georgetown Pike
McLean, Virginia 22101-2296
- Contracting Officer's Technical Representative (COTR):
- Howard H. Bissell, HSR-30 and Davey L. Warren, HSR-10.
- Contract or Grant Number:
- DTFH61-85-C-00136.
- HTMLised by:
- Kevin Atkinson, kevinatk@home.com
Under Contruction. Figures and the rest of the text to be added soon.
Table of Contents
The entire report is 84 pages long. You can try calling the National
Technical Information Service (general info 703-487-4770, sales
703-487-4650) and asking for this report. Even with the report number
they won't be able to find it. It's being buried since it says things
that certain organizations (both governmental and private) don't want
to be made public. However, NMA is selling this report for $15 plus
$4 shipping and handaling. They can be contacted at 608/849-6000;
nma@motorists.com
; or 6678 Pertzborn Road, Dane, Wisconsin 53529.
This page is part of a larger
Reasonable Drivers Unanimous
site. Be sure to check the rest of my site out if this is your first time
visiting. You won't regret it!
Related Documents
Related Pages
Back Home
| Start