DRIVER RESPONSE TO THE 55-MPH MAXIMUM SPEED LIMIT AND VARIATIONAL CHARACTERISTICS OF SPOT SPEEDS

Spot speed observations were made on a four-lane suburban freeway from November 8, 1973, to June 13, 1974, when speeds were influenced by fuel conservation measures. Speeds were recorded in 15-min intervals in mid-afternoons on 39 days. The mean speed of cars dropped from 63.4 mph (102 km/h) in early November to 60.4 mph (97.2 km/h) in late November to early March and was further reduced to 57.4 mph (92.4 km/h) after the posted speed limit was changed from 70 to 55 mph (113 to 88 km/h) on March 3, 1974. A multiple classification analysis of the 15-min mean speeds showed that the variance of these means was not significantly affected by factors such as time of day, day of the week, traffic flow, and truck composition, although an effect due to different observers was found. The residual variance of the 15-min means after systematic effects were removed was significantly greater than would be expected from sampling errors if the speeds of individual cars were identically distributed. The implications of these results with respect to the planning and design of before and after speed studies are discussed.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1976/567/567-010.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=DRIVER+RESPONSE+TO+THE+55-MPH+MAXIMUM+SPEED+LIMIT+AND+VARIATIONAL+CHARACTERISTICS+OF+SPOT+SPEEDS&author=T.+Lam&author=P.+Wasielewski&publication_year=1976
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• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Traffic Flow Theory and Characteristics Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Lam, Tenny N
  • Wasielewski, Paul
• Conference:
  • 54th Annual Meeting of the Transportation Research Board
  • Location: Washington District of Columbia
  • Date: 1975-1-13 to 1975-1-17
• Publication Date: 1976

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 91-97
• Monograph Title: Traffic flow theory and applications
• Serial:
  • Transportation Research Record
  • Issue Number: 567
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Before and after studies; Drivers; Four lane highways; Reaction time; Speed limits; Spot speed; Studies; Traffic speed
• Uncontrolled Terms: Driver reaction
• Old TRIS Terms: Speed studies
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00139880
• Record Type: Publication
• ISBN: 0309024803
• Files: TRIS, TRB
• Created Date: Oct 6 1976 12:00AM