Applying Techniques to Increase Warning of Signals Beyond Vertical Curves (5-4084-01-1)

This implementation project was designed to improve the utilization of the recommendations and findings from TxDOT research project 0-4084," Countermeasures to Reduce Crashes at Signalized Intersections near Vertical Curves." The original research identified the conditions under which motorists approaching a vertical curve could not see ahead with decision sight distance due to the artificial horizon created by the curve. The crest of the curve, in turn, could prevent motorists from seeing a queue of vehicles at a signal beyond the curve, and possibly even the signal itself. Researchers developed guidelines for the type and location of supplemental, advance warning signing to provide advanced motorist notification of this situation during project 0-4084. Providing Texas Department of Transportation staff and other potential users with the guidelines and recommendations of project 0-4084 was the primary goal of the implementation effort. This report thoroughly documents the application of project 0-4084 guidelines to study sites in Austin and Laredo, Texas. Site conditions are described in detail and the complete process of signing and communications design, field installation, and field review is documented. This report is most effectively used in conjunction with implementation product 5-4084-01-P1, a digital video disc ( i.e., DVD) that provides video and audio documentation of the site conditions, signing design and application of 0-4084 findings, installation and results of both field installations.