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/ Scoping Study: Vertical Visibility Constraints -- Vertical Curvature Traffic Control Devices https://rip.trb.org/View/2709249 Tue, 02 Jun 2026 13:49:43 GMT https://rip.trb.org/View/2709249 New Models and Solutions to Vehicle Routing with Cardinality and Distance Constraints https://rip.trb.org/View/2703788 Sat, 16 May 2026 11:45:53 GMT https://rip.trb.org/View/2703788 Using Head-Mounted Virtual Reality to Measure Dynamic Driver Sight Distances and Blind Spots https://rip.trb.org/View/2625595 Mon, 17 Nov 2025 14:56:41 GMT https://rip.trb.org/View/2625595 Tour Generation of Interregional Travel in the United States: Insights from the 2017 National Household Travel Survey (NHTS) https://rip.trb.org/View/2459118 Sat, 23 Nov 2024 10:58:17 GMT https://rip.trb.org/View/2459118 Developing a Prototype System for Measuring Intersection Sight Distances https://rip.trb.org/View/2437841 Mon, 07 Oct 2024 16:01:56 GMT https://rip.trb.org/View/2437841 Assessing Pedestrian Sight Distance for Crossing Decisions https://rip.trb.org/View/2381747 Thu, 23 May 2024 10:06:12 GMT https://rip.trb.org/View/2381747 Developing sight distance guidelines for U-turn maneuvers https://rip.trb.org/View/2339986 Thu, 15 Feb 2024 14:41:43 GMT https://rip.trb.org/View/2339986 What Is the New Normal? An Analysis of Post-COVID-19 Commute and Work Patterns https://rip.trb.org/View/2087424 Wed, 21 Dec 2022 10:56:34 GMT https://rip.trb.org/View/2087424 Guide for Marked Crosswalk Design, Spacing, Placement, and Safety https://rip.trb.org/View/1953235 Mon, 16 May 2022 18:09:37 GMT https://rip.trb.org/View/1953235 Implication of School Format on Women in STEM https://rip.trb.org/View/1740572 Wed, 18 Nov 2020 17:07:30 GMT https://rip.trb.org/View/1740572 Transportation Learning Network https://rip.trb.org/View/1724200 Mon, 27 Jul 2020 15:40:14 GMT https://rip.trb.org/View/1724200 RES2020-19: Activity-based Household Travel Survey through Smartphone Apps in Tennessee https://rip.trb.org/View/1716836 Mon, 29 Jun 2020 14:38:17 GMT https://rip.trb.org/View/1716836 Environmental Justice Implications of Roadway Topography  https://rip.trb.org/View/1635480 Thu, 04 Jul 2019 10:48:54 GMT https://rip.trb.org/View/1635480 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 Field Aging Effects on Asphalt Mixed at Different Temperatures and Hauled Different Distances https://rip.trb.org/View/1508231 Mon, 09 Apr 2018 13:53:43 GMT https://rip.trb.org/View/1508231