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/ Research for AASHTO Standing Committee on Highways. Task 405. Reevaluation of the Perception and Reaction Time and Deceleration Rates for Stopping https://rip.trb.org/View/1877228 Tue, 07 Sep 2021 13:36:44 GMT https://rip.trb.org/View/1877228 Development of the 8th Edition of AASHTO's A Policy on the Geometric Design of Highways and Streets (Green Book) https://rip.trb.org/View/1707200 Wed, 20 May 2020 18:31:24 GMT https://rip.trb.org/View/1707200 Research for AASHTO Standing Committee on Highways. Task 398. Development of Performance-Based Geometric Design Content for the Next Edition of the AASHTO Green Book https://rip.trb.org/View/1673343 Tue, 17 Dec 2019 12:14:50 GMT https://rip.trb.org/View/1673343 Update of the Policy on Geometric Design of Highways and Streets Guidance on Acceleration/Deceleration and Stopping Sight Distance Criteria https://rip.trb.org/View/1628617 Sat, 08 Jun 2019 05:14:54 GMT https://rip.trb.org/View/1628617 An Update of the Green Book Design Vehicles Requirements https://rip.trb.org/View/1516155 Mon, 18 Jun 2018 19:33:12 GMT https://rip.trb.org/View/1516155 Operational and Safety Considerations in Making Lane Width Decisions on Urban and Suburban Arterials https://rip.trb.org/View/1331125 Tue, 18 Nov 2014 01:00:43 GMT https://rip.trb.org/View/1331125