The purpose of curve warning signs and travel path delineation devices is to alert drivers to the presence and severity of a downstream horizontal curve. The advisory speed plaque is the primary device for conveying the appropriate speed message to drivers, but additional devices such as chevrons are often used at sharp curves to emphasize the curvature. This paper describes the development and evaluation of guidelines for selecting traffic control devices for horizontal curves on rural highways. The developed guidelines are based on considerations of side friction and kinetic energy. These guidelines incorporate a curve speed model that was calibrated using data from 41 curve sites in Texas. The developed guidelines are also compared with the guidelines in the 2007 proposed amendments to the Manual on Uniform Traffic Control Devices, which are based on considerations of speed differential.