Horizontal road markings for human and machine vision

Abstract

Horizontal road markings are inalienable feature on almost all roads because their presence results in significant increase in safety for all road users. By providing delineation, they help drivers in keeping the vehicle in the traffic lane. At night time, retroreflectivity (RL) of road markings, achieved by incorporating glass beads on the marking surface, is perceived by the drivers and its level was reported to be associated with lower accident rate. Indeed, usable life of road markings is measured by their RL. It is shown herein, based on field tests, that for thick-layer structured road marking systems the selection of glass beads has profound effect not only on retroreflectivity, but also on durability. Exemplary financial analysis demonstrates that despite higher one-time expense, savings can be realised in the long-term with the use of premium materials. Moreover, the same high quality and high RL of horizontal road markings that are needed for human drivers are demanded by machine vision algorithms, which provides guidance in the emerging autonomous vehicles technology. Therefore, maintaining of horizontal road markings at high level is necessary — until all of the vehicles would be self-driving, and very possibly even afterwards. Furthermore, because of reasonable price and broad availability, durable horizontal road markings have a potential of being one of the solutions to lower accident occurrences in poorly developed countries.