Degradation of the Retroreflectivity of Thermoplastic Pavement Markings in Bangkok Highways

Road traffic markings serve as signals that govern the position and direction of vehicle operation, providing drivers with information to steer their vehicles within traffic lanes and apply proper acceleration and deceleration for safe movement on the road. Therefore, visibility of road markings is crucial, especially during nighttime or in conditions with low illumination. Driving at night becomes less dangerous when there are clearly visible road markings. The visibility of road markings at night can be measured by the retroreflectivity [1]. This study aims to investigate the deterioration of road traffic markings in Bangkok. It involved selecting four-lane roads with different ages of traffic markings within the range of 0-24 months. Random positions were chosen to measure the retroreflectivity of road traffic markings at every 500-meter interval. The analysis, conducted using linear regression, revealed that the retroreflectivity value of road traffic markings varies with their age, traffic exposure and percent of trucks and is influenced by the thickness of the markings. Additionally, the study found statistically significant differences in retroreflectivity values based on the positions of the road traffic markings.