Several factors are considered within engineering studies when determining the posted speed limit, including the 85th percentile speed during free-flow conditions and the segment’s crash history. TRB hosted a webinar on Monday, July 26, 2021, from 2:00-3:30 PM Eastern that discussed a new speed limit setting procedure and tool (SLS-Tool) developed to aid in making informed decisions about the setting of speed limits. The development of the SLS-Tool considered previous research along with current research data from Austin, Texas and Washtenaw County, Michigan. 

This webinar features research from NCHRP Research Report 966: Posted Speed Limit Setting Procedure and Tool, NCHRP Web-Only Document 291: Development of a Posted Speed Limit Setting Procedure and Tool, and two versions of the SLS-Tool:
N17-76 SLS-Tool (with macros) and N17-76 SLS-Tool (without macros)

The slides and recording are available. 

Webinar agenda and presenters

1. Overview: Kay Fitzpatrick, Texas A&M Transportation Institute
2. Findings from Michigan: Tim Gates, Michigan State University
3. Findings from Texas: Kay Fitzpatrick, Texas A&M Transportation Institute
4. SLS Procedure and Tool demonstration: Michael Pratt, Texas A&M Transportation Institute
5. Question and answer session: Moderated by Kevin Haas, Oregon Department of Transportation

The first 60 minutes of the webinar will be for presentations and the final 30 minutes will be reserved for audience questions.

Learning Objectives

At the end of this webinar, participants will be able to:

1. Identify factors that determine speed limits
2. Compute a suggested speed limit using the SLS tool

Professional Development Hours

Professional Development Hours (PDHs) earned on completion of this program were reported to the Registered Continuing Education Program (RCEP). Certificates of Completion are issued to all participants via the RCEP.net online system. Complaints about registered providers may be addressed to RCEP, 1015 15th Street, NW, 8th Fl., Washington, DC, 20005.