This research was initiated to show if roadway delineation systems could be designed to affect driver behaviour in negotiating rural curves at night through early warning and better lane guidance. After laboratory tests in lateral and vertical placement effectiveness of delineators and field evaluation of various delineator types, eight systems were deployed on six rural curves to ascertain before-after delineation treatment effects, effects due to curve direction, day versus night, high speed drivers, and the effect of treatment on test driver visual search. Road user velocities at six points before and into the curve as well as curve lateral placement were recorded. Results indicate that novel use of delineators can provide positive perceptual influences and cause drivers to reduce speeds prior to and into rural curves. Centerline encroachments are usually reduced with these treatments. The better systems were raised pavement markers (life lites), ascending in/out deployment of delineators and transverse striping. High speed drivers were shown to react differently than the average driver suggesting they may make use of delineators to further their high speed objectives. While novel delineation systems were more effective in velocity reduction and lateral placement in the curve as compared to the design in the manual for uniform traffic control devices (MUTCD), the MUTCD system was significantly better than the same curves without any delineation. The effects of these delineation treatments were insignificant 30 days after installation suggesting effects would be found for transient or unfamiliar drivers rather than local drivers. (Author/publisher)
Abstract