Acceleration, deceleration, and stopping sight distance (SSD) criteria are key factors in determining roadway geometric design requirements. These elements are influenced by variables such as grade, vehicle type, maneuver type, brake reaction time, object height, and driver’s eye height. TRB will host a webinar on Thursday, February 6, 2025 from 1:00 PM to 2:30 PM Eastern that will cover the findings from recent studies that assess design policies related to these criteria and informed recommendations for updates to the AASHTO Green Book.
This webinar is based on NCHRP Research Report 1081: Acceleration, Deceleration, and Stopping Sight Distance Criteria for Geometric Design of Highways and Streets.
This webinar is sponsored by TRB’s National Cooperative Highway Research Program and the Standing Technical Committee on Performance Effects of Geometric Design.
Registration is free for employees of TRB sponsors as well as Titanium and Cobalt Global Affiliates. The registration rate for all other attendees is $100. Sign into MyTRB.org to view registration information.
A recording will be sent to all registrants after the webinar.
 
Webinar agenda and presenters

• Overview of NCHRP 15-75 and related field and crash studies – Peter T. Savolainen, Michigan State University
• Development of revised design guidelines – Eric T. Donnell, Pennsylvania State University
• Translating results into practice – James A. Rosenow, Minnesota Department of Transportation
• Question and answer session moderated by Eric T. Donnell, Pennsylvania State University

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:

• Understand the differences between current design assumptions and associated parameters that describe driver behavior and vehicle performance
• Design acceleration and deceleration lanes in consideration of revised guidance based on driver behavior
• Determine the recommended SSD for various scenarios and relate anticipated safety performance to available sight distance

 
Professional Development Hours
Professional engineers (PEs) who register and attend the entire webinar as an individual will be awarded 1.5 Professional Development Hours (PDHs). TRB’s webinar program awards PDH credits only to the registered individual, and not to other members of a group that view the webinar together. To be eligible for the credits, individuals must remain signed in for the entire webinar, including for any question and answer session following the presentations.
This webinar will be delivered as a scheduled – e-learning live event and is categorized within RCEP as Technical, Health and Safety.
Please check with your licensing board to ensure that TRB webinar PDHs are approved by your board.
TRB will report credits earned to the Registered Continuing Education Program (RCEP). Complaints about registered providers may be sent to RCEP, 1015 15th Street, NW, 8th Floor, Washington, D.C., 20005.
 
Pre-registration is required. Once the webinar starts, you will be unable to register. Individuals that are registered for a webinar but do not receive their confirmation emails due to their organization’s internal firewalls should contact TRB Helpdesk for assistance in signing in.
View our FAQ page for more information.
Registration questions? Contact TRB webinar program.