Transport Research International Documentation (TRID) https://trid.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) Transport Research International Documentation (TRID) https://trid.trb.org/Images/PageHeader-wTitle.jpg https://trid.trb.org/ INSTRUMENTAL COLORIMETRY OF RETROREFLECTIVE SIGN MATERIALS https://trid.trb.org/View/23683 Sat, 29 May 1976 00:00:00 GMT https://trid.trb.org/View/23683 INSTRUMENTAL COLOR MEASUREMENT OF RETROREFLECTIVE HIGHWAY SIGN MATERIALS https://trid.trb.org/View/112861 Mon, 05 Jun 1972 00:00:00 GMT https://trid.trb.org/View/112861 INSTRUMENTAL COLOR MEASUREMENT OF RETROREFLECTIVE HIGHWAY SIGN MATERIALS https://trid.trb.org/View/108079 Tue, 15 Feb 1972 00:00:00 GMT https://trid.trb.org/View/108079