CT DOT Study proves motorists drive faster on double-yellow lines

DESIGNING ROADS THAT GUIDE DRIVERS TO CHOOSE SAFER SPEEDS November 2009 John N. Ivan Norman W. Garrick Gilbert Hanson JHR 09-321 Project 04-6 SECTION 2.6 The effect of road markings on driver behavior in influencing speed has been the subject of numerous small-scale studies. To make generalized deductions from these small studies, some researchers have conducted meta-analysis so as to establish the underlying relationship among the numerous findings. A meta-analysis on the effect of altered road markings on speed and lateral position by Davidse et al. (2004), suggested that roads that exhibited significant increases in mean speed were roads that prior to the introduction of edge lines had no road markings of any type. Their research further indicated that introducing a centerline marking to a road that has no markings yields a similar result. They attributed the increases in speeding to the improvement in visual guidance provided by the road markings. Unfortunately, while the lane marking impacts 7 positively in reducing the risk of run-off-the-road crashes, it is counterproductive to efforts aimed at reducing the operating speed on roadway segments. http://www.ct.gov/dot/LIB/dot/documents/dresearch/JHR_09-321_JH_04-6.pdf