Self-explaining performance of visual guiding facilities in urban road tunnels based on speed perception.

• Self-explaining performance of vertically facilities for SSES and PRT is better. • The closer actual speed of the test scene is to the SSES, the greater PRT. • Combined of contour and alignment guidance can play better self-explaining effect. A low-cost and effective speed control method is to be developed for urban road tunnels in order to enhance traffic safety and improve operation in the tunnels. The self-explaining performance of the visual guiding facilities on driver's speed perception and reaction time in the interior zone of urban tunnels was investigated. Using 3D Max to build video simulation model, and referring to the common visual guiding facilities in urban tunnels, six scenes were constructed, namely no facility, horizontal stripe, edge marker, retroreflective arch, vertical stripe and multiple facilities. Stimulus of subjectively equal speed (SSES) and perception reaction time (PRT) were selected as the basic performance indicators to evaluate the different scenes. The experimental results showed that the SSES in multiple facilities scene was closest to the standard speed, followed by the vertical stripe, retroreflective arch, horizontal stripe, and no facility, while speed over-estimation was the most serious in edge marker scene. The results of PRT also showed that self-explaining performance of PRT in multiple facilities and vertical stripe scenes was better than other facilities. Vertically spaced facilities had better SSES and PRT self-explaining performance. The reasonable combination of different types of visual guiding facilities can integrate the advantages of each facility, which is more conducive to realizing the self-explaining effect of rapid perception, accurate judgment, timely decision and easy manipulation. [ABSTRACT FROM AUTHOR]