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/ Improving Vehicle Cabin Air Quality in Daily Transportation https://rip.trb.org/View/2652182 Tue, 13 Jan 2026 14:25:51 GMT https://rip.trb.org/View/2652182 Washington Metropolitan Area Transit Authority Enhanced Covid-19 Rail Car Air Filtration and Air Purification Research Demonstration https://rip.trb.org/View/2067957 Mon, 21 Nov 2022 16:26:08 GMT https://rip.trb.org/View/2067957 Transit Vehicle Enhancements to Mitigate Exposure and Strengthen Confidence in Transit for Riders, Drivers and Staff https://rip.trb.org/View/2067955 Mon, 21 Nov 2022 16:26:07 GMT https://rip.trb.org/View/2067955