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/ Observational Intersection Traffic Safety Analysis https://rip.trb.org/View/2655705 Mon, 19 Jan 2026 16:30:17 GMT https://rip.trb.org/View/2655705 Evaluating Safety Impacts of Permissive Green Signal Phasing on Observed Conflicts Between Left-Turning Vehicles and Pedestrians https://rip.trb.org/View/2625837 Mon, 17 Nov 2025 18:34:21 GMT https://rip.trb.org/View/2625837 Sequencing for Phases with Flashing Yellow Arrow https://rip.trb.org/View/2608463 Mon, 13 Oct 2025 18:57:17 GMT https://rip.trb.org/View/2608463 Improve Safety of Vehicles and Vulnerable Road Users at Intersections Integrating C-V2X and LiDAR Sensing Technologies https://rip.trb.org/View/2447164 Wed, 30 Oct 2024 15:29:40 GMT https://rip.trb.org/View/2447164 Integrating Progression Band and Delay Optimization for Arterials with Unbalanced Directional Traffic https://rip.trb.org/View/2343710 Thu, 22 Feb 2024 15:54:19 GMT https://rip.trb.org/View/2343710 Improving Crash Prediction Using GRIDSMART Infrastructure https://rip.trb.org/View/2325689 Mon, 22 Jan 2024 09:44:56 GMT https://rip.trb.org/View/2325689 Field-Based Evaluation of Left Turn Behavior Variations at the Individual Driver/Vehicle Level https://rip.trb.org/View/1853639 Mon, 24 May 2021 11:28:27 GMT https://rip.trb.org/View/1853639 Effect of Large Vehicles on Left Turn Gap Acceptance at Signalized Intersections https://rip.trb.org/View/1705307 Thu, 07 May 2020 12:53:50 GMT https://rip.trb.org/View/1705307 Reasonable Alternatives for Grade-Separated Intersection https://rip.trb.org/View/1472678 Fri, 30 Jun 2017 15:37:25 GMT https://rip.trb.org/View/1472678 Evaluation of Diverging Diamond Interchanges for Alabama, Phase I https://rip.trb.org/View/1260467 Fri, 30 Aug 2013 01:01:01 GMT https://rip.trb.org/View/1260467 Improving Transportation Performance: The Case of Left Turns https://rip.trb.org/View/1239204 Thu, 31 Jan 2013 01:01:19 GMT https://rip.trb.org/View/1239204