National Cooperative Highway Research Program (NCHRP) Project 3-61
Richard Lyles and William Taylor, Department of Civil and Environmental Engineering
Joe Hummer, North Carolina State University; Fred Vansodall, consultant
This NCHRP-funded project is concerned with the development of recommendations and consistent approaches to the use of traditional curve-related traffic control devices (TCDs) including both the warning signs for the curves themselves (e.g., curve and turn arrows) and speed advisory plates. While curve-related warning signs are easily among the most common and recognizable to motorists, their use remains inconsistent from one jurisdiction to another and sometimes within jurisdictions. The inconsistency is especially apparent in determining (and then marking) the appropriate advisory speeds.
The project includes assessing the state of the art and the state of practice (nationally) through surveys and focus groups of practitioners, obtaining information from average motorists as well as those who have been involved in vehicle crashes on curves (again, using surveys and focus groups), undertaking field-based evaluations of motorist reactions to different signing scenarios, and, ultimately, developing guidelines for deploying the most effective traffic control devices in specific situations. Device evaluations will be done in both Michigan and North Carolina to assess any regional differences in effectiveness.
This project is an extension of many years of work with TCDs. In general, this work has been based on overt and covert measurement of motorist reactions in the field, determination of the safety-related impacts of different TCDs, focus group research regarding driver perception and preference, and linking device effectiveness to demographic differences (most specifically, driver age).
Department of Civil and Environmental Engineering
3546 Engineering Building
Michigan State University
East Lansing, MI 48824-1226