Transport Research International Documentation (TRID) https://trid.trb.org/ en-us Copyright © 2024. 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) Transport Research International Documentation (TRID) https://trid.trb.org/Images/PageHeader-wTitle.jpg https://trid.trb.org/ Development of a Field Guide for Portable Changeable Message Sign Use in Work Zones https://trid.trb.org/View/767633 Fri, 16 Dec 2005 12:23:47 GMT https://trid.trb.org/View/767633 GUIDELINES ON THE USE OF CHANGEABLE MESSAGE SIGNS - SUMMARY REPORT https://trid.trb.org/View/361506 Fri, 31 Jan 1992 00:00:00 GMT https://trid.trb.org/View/361506