Considering Roadway Context in Setting Posted Speed Limits. Issue 8 (August 2021)

• Record Type: Journal Article
• Authors: Fitzpatrick, Kay; Das, Subasish; Gates, Timothy; Dixon, Karen K.; Park, Eun Sug
• Is Part Of: Transportation research record. Volume 2675:Issue 8(2021)
• Page Start: 590
• Page End: 602
• Publication Date: 2021-08
• Subjects: Transportation -- Periodicals; Roads; Transport -- Périodiques; Routes -- Périodiques; Routes -- Conception et construction -- Périodiques; Roads; Transportation; 388.05
• DOI: 10.1177/0361198121999618
• Languages: English
• ISSNs: 0361-1981

Abstract

The National Cooperative Highway Research Program (NCHRP) Project 17-76 investigated factors that influence operating speed and safety through a review of the literature and an analysis of the relationships for speed, safety, and roadway characteristics on urban/suburban streets. That knowledge, along with a review of existing speed limit setting practices, was used to develop a Speed Limit Setting Procedure (SLS-Procedure) as well as a user manual to explain the SLS-Procedure. In addition, the SLS-Procedure was automated via a spreadsheet-based Speed Limit Setting Tool (SLS-Tool). These products will permit engineers to make informed decisions about the setting of speed limits. The SLS-Procedure is fact based and transparent, relying on a set of decision rules that consider both driver speed choice and safety associated with the roadway. The SLS-Procedure was designed to be applicable across different roadway types and contexts by having a set of unique decision rules for four combinations of roadway types and contexts: limited-access, undeveloped, developed, and full-access facilities. The SLS-Procedure uses the operating speed distribution as a starting point for the suggested speed limit, with the resulting suggested value based on consideration of roadway type, context, safety performance, and other characteristics.