Relating Subjective Ride Quality Ratings to Objective Measures

Abstract

Agencies have long used subjective roughness ratings from panels of users to inform policy development on road maintenance strategies. The commoditization of electronics motivated the development of more objective, automated, and cost-effective measurement technologies. Consequently, there has been an explosion of ensemble measurements using smartphones or connected vehicles. Nevertheless, agencies have no means of relating those sensor-based measurements to their customary linguistic scale of human perceived roughness levels. This research relates subjective ratings of roughness from regular passengers of public bus transit to simultaneous smartphone-based objective measures of roughness. The findings are that regular bus riders consistently distinguished between the extreme values of measured roughness but not the intermediate values. Ratings are also less distinguishable for smoother rides than for rougher rides. The experiments also reveal a phenomenon of roughness acclimation that leads to biased ratings from regular users of a road segment.