The speed control effect of highway tunnel sidewall markings based on color and temporal frequency

Abstract

Summary The low‐luminance monotonous environment in the middle section of highway tunnels offers few reference points and is prone to cause severe visual illusion. Thus, drivers tend to underestimate their driving speed, which can induce speeding behaviors that result in rear‐end collisions. Therefore, discovering low‐cost methods of traffic engineering that reduce this visual illusion and ensure a steady driving speed is an important challenge for current highway tunnel operations. This study analyzes the effects of sidewall markings in typical highway tunnels, specifically observing how their colors and temporal frequencies affect the driver's speed perception in a low‐luminance condition. A three‐dimensional model of the middle section of highway tunnels was built in a driving simulator. Psychophysical tests of speed perception were carried out by the method of limits. The precision of the simulation model was then checked by comparing the results to field test data. The simulation tests studied the stimulus of subjectively equal speed and reaction time in relation to sidewall markings in different colors (red–white combined, yellow–white combined, and blue–white combined). Furthermore, based on the optimal color, the effects of sidewall marking with different temporal frequencies (0.4, 0.8, 1.2, 2, 4, 8, 12, 16, and 32 Hz) on the speed perception of drivers were also analyzed. The test results reveal that the color and temporal frequency of sidewall marking have a significant impact on the driver's stimulus of subjectively equal speed and reaction time. The subjects have the highest speed overestimation and an easy speed judgment with the red–white combined sidewall marking. Within the temporal frequency range of 4.45–7.01 Hz, the subjects have a certain degree of speed overestimation (less than 20%), and the speed perception is sensitive to the temporal frequency changes. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluating the Effectiveness of Speed Reduction Markings in Highway Tunnels

“…It is probably due to the lack in the drivers' peripheral vision of the visual stimulations compared to open road sections. In the field, information from the surrounding landscape is often used unconsciously by drivers as an external reference for speed perception (Wan et al 2016). What's more, lighting is certainly a primary factor that affect the driving performance in highway tunnels.…”

Influence of multiscale visual information on driver’s perceived speed in highway tunnels

“…The results in Table 3 and Figure 7 reveal the following: Speed illusion = (speed in the standard scene -SSES) / speed in the standard scene. 23 '-' in speed illusion denotes speed underestimation. ' 6 ' in SSES represents standard deviation.…”

“…Moreover, a spacing of 10-20 m between markings could effectively improve drivers' sense of their speed. Wan et al 22,23 investigated the effect of high-frequency visual information and a combination of high-and medium-frequency visual information on the sense of speed and reaction time of drivers under different levels of illumination (100%, 50% and 25% standard illumination) in tunnels, specifically observing how colours and temporal frequencies affected a driver's speed perception under the low-luminance conditions of tunnels. The results show that good illumination conditions and multifrequency visual information were beneficial in enhancing driver sensitivity to driving speed and preventing unconscious acceleration when driving in the middle of tunnels at high speeds.…”

“…Driving simulator experiments have been widely applied in driving behaviour studies as well as speed perception studies. 18,[20][21][22][23] Although most simulators involve a flat, two-dimensional (2D) display and not a three-dimensional (3D) display, the simulated speeds are highly correlated with real-world performance data, 24 and during driving, a simulator can perceive the impact of contrast reduction on speed perception. 12 The presence of stereoscopic cues regarding motion in depth can significantly enhance the precision of speed judgements; however, the accuracy of speed judgements is unaffected by it, with satisfactory performance being achieved under the 2D condition.…”

“…Current research on visual illusion markings suggests that high-frequency visual information makes a driver overestimate his own driving speed, while low-frequency visual information may induce a speed underestimation. 19,20,23 Thus, highfrequency pavement markings have been used widely to enhance the speed perception of drivers on highways. However, quantitative investigation of the influence of visual information with frequency and scale on the occurrence of driver visual illusion in tunnels is limited.…”