As an implementation strategy of the federal retroreflectivity standards requirement for pavement markings, the New Jersey Department of Transportation (DOT) evaluated its 3-year fixed-schedule restriping strategy, to determine if it is consistent with the actual service life of the pavement markings. The methodology and results of the study are presented. Two types of data were collected: measured retroreflectivity by using LaserLux and subjective ratings from a survey conducted with the participation of the New Jersey driving public along a 32-mi circuit. Multiple regression techniques were used to correlate the average scores reported by the study participants for each specific roadway section with the corresponding measured retroreflectivity. The results suggested that the threshold value of an acceptable versus unacceptable level of retroreflectivity appeared to be between 80 and 130 mcd/sq m/lux for New Jersey drivers younger than 55 and between 120 and 165 mcd/sq m/lux for drivers older than 55. These results are consistent with conclusions reached by other investigators in similar research, where results generally ranged between 70 and 170 mcd/sq m/lux. Interim visibility indices were developed for each age group per pavement-marking type. New Jersey DOT used the indices to determine and prioritize needs and to quantify needed related resources, on the basis of the threshold between acceptable retroreflectivity and unacceptable retroreflectivity, when it developed its pavement-marking management system. This approach also allows for cost-benefit and life-cycle analysis for different pavement-marking materials.
Abstract