Research in Progress (RIP) https://rip.trb.org/ en-us Copyright © 2026. National Academy of Sciences. All rights reserved. http://blogs.law.harvard.edu/tech/rss tris-trb@nas.edu (Bill McLeod) tris-trb@nas.edu (Bill McLeod) Research in Progress (RIP) https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg https://rip.trb.org/ SPR-5017: Safety Performance of Setting Speed Limits Based on Roadway Alignment https://rip.trb.org/View/2600573 Tue, 16 Sep 2025 10:36:08 GMT https://rip.trb.org/View/2600573 Tools for Managing Speed Based on Factors Influencing Driver Speed Selection https://rip.trb.org/View/2558369 Thu, 29 May 2025 13:06:30 GMT https://rip.trb.org/View/2558369 Impacts of Turn Lanes on Speed and Crashes Involving Vulnerable Road Users in Urban Areas https://rip.trb.org/View/2558380 Wed, 28 May 2025 14:15:47 GMT https://rip.trb.org/View/2558380 RES2023-24: Informed Safety, Mobility and Driver Comfort Enhancement Practices for Work Zones https://rip.trb.org/View/2480317 Fri, 03 Jan 2025 12:03:13 GMT https://rip.trb.org/View/2480317 Designing for Target Speed https://rip.trb.org/View/2437305 Mon, 30 Sep 2024 17:13:25 GMT https://rip.trb.org/View/2437305 Speed Impacts from Roundabouts and Other Traffic Control Devices https://rip.trb.org/View/2414011 Wed, 07 Aug 2024 09:25:08 GMT https://rip.trb.org/View/2414011 Effect of Centerlines on Prevailing Traffic Speeds on Low-Speed, Two-Lane, Two-Way Roads in Urban Contexts https://rip.trb.org/View/2406777 Wed, 24 Jul 2024 10:18:22 GMT https://rip.trb.org/View/2406777 Effectiveness of Speed Reduction in Work Zones https://rip.trb.org/View/2255669 Tue, 26 Sep 2023 16:46:26 GMT https://rip.trb.org/View/2255669 How Much Pedestrian Harm Can We Attribute to Larger Vehicles in the Fleet? https://rip.trb.org/View/2229412 Thu, 17 Aug 2023 16:58:06 GMT https://rip.trb.org/View/2229412 Relationship of Speed, Roadway Geometrics, and Crashes on High-Speed Rural Highways https://rip.trb.org/View/1957066 Mon, 23 May 2022 16:12:46 GMT https://rip.trb.org/View/1957066 SPR-4640: Geometric Constraints and Visual Field Related to Speed Management https://rip.trb.org/View/1898912 Mon, 20 Dec 2021 16:31:13 GMT https://rip.trb.org/View/1898912 Impact of Pavement Friction on Traffic Safety, Phase 1:Pavement Friction Evaluation https://rip.trb.org/View/1722361 Wed, 15 Jul 2020 17:17:39 GMT https://rip.trb.org/View/1722361 Deflection Angle Effect on Continuous Driver Performance Along Horizontal Curves https://rip.trb.org/View/1705269 Thu, 07 May 2020 08:17:23 GMT https://rip.trb.org/View/1705269 Convoluted Gaussian Process (CGP): An Alternative to Facilitate Analysis and Predictions of Multiple DPMs under Several Driving Conditions Using Driving Simulators https://rip.trb.org/View/1705267 Thu, 07 May 2020 08:11:24 GMT https://rip.trb.org/View/1705267 Driver Behavior and Performance in High to Low Speed Transitions https://rip.trb.org/View/1672446 Wed, 11 Dec 2019 15:54:14 GMT https://rip.trb.org/View/1672446