Do wider longitudinal road markings influence driving speed perception?

Excessive speed is one of the factors most frequently associated with traffic accidents and noncompliance with traffic regulations. Road markings serve as a fundamental aid for drivers, with their design playing a critical role in road safety. Wider longitudinal markings create a visual narrowing effect on the driving lane, potentially increasing the perception of speed and encouraging drivers to reduce their speed, thereby enhancing traffic safety. However, this phenomenon has received limited attention in prior studies, which have predominantly relied on field experiments with small sample sizes and have often overlooked important variables such as night driving conditions. Given these considerations, the objective of the present study is to examine whether the perception of speed while driving on curves increases with the use of wider longitudinal markings compared to those established by traffic regulations. To address this objective, video recordings were made of vehicles navigating 6 curves under 2 conditions: With standard longitudinal markings and with modified, wider markings. Subsequently, a survey was conducted with 2,419 participants. The participants were shown the videos and asked to identify in which segments they perceived greater vehicle speed. The findings revealed that the likelihood of perceiving greater speed on curves with wider markings was significantly higher in the following cases: Female participants, drivers who had not caused an accident or received a traffic ticket in the past 5 years, those with greater driving experience, higher vehicle speeds, viewing standard markings prior to the wider ones, navigating right-oriented curves, and nighttime driving conditions. These results demonstrate that the application of wider longitudinal road markings can, in general, enhance the perception of speed on curves. This effect has the potential to improve road safety by promoting slower driving behavior.