An experimental study on the effect of sequential transverse and lateral markings on perceived speed in curved road

For the purpose of enhancing road markings to prevent speeding on curved road, we focused on the vehicle speed inducement effect of sequence patterns of sequential transverse and lateral markings on a straight section of roadway leading into a transition section of the curved road. We tested the effectiveness of several sequence patterns through a driving simulation experiment with a driving simulator (DS) and a driver perception experiment with recorded moving pictures (MPs). The sequence patterns were characterised by patterns of progressively and concurrently reduced spacing of transverse lines on the lane surface and lateral poles on both the shoulder edge and the median strip. While estimating trends in spot speed that was perceived by a driver (test subject) who went into the curve entrance under the influence of sequence patterns, we examined a discrepancy between the perceived speed transition and the vehicle speed transition, by using hidden Markov model (HMM) on the estimation. We prepared four types of the sequence patterns including the types which had greater decrease rates of the intervals of spacing in the beginning, middle, and end sections than in the remaining sections among all the sections consisting of the pattern. The experimental results concluded that the sequence pattern type which had greater decrease rates in the end section than in remaining sections might be encouraged to be laid on the curved road, in terms of a safe vehicle speed inducement effect.