Enhanced Decision-Making Framework for the Southern States to Comply with the New Federal Retroreflectivity Pavement Rule

Retroreflectivity plays a crucial role in pavement markings as it enhances nighttime visibility for drivers. Yet, due to budget constraints, many state U.S agencies including the Texas Department of Transportation (TxDOT) rarely monitor the retroreflectivity of their markings, and instead, restripe their markings based on visual inspection or fixed schedule (every two years). Such a strategy is questionable in terms of safety as markings are usually restriped after the end of their service life. To address this issue, in August 2022, the Federal Highway Administration (FHWA) announced a new final rule that requires state agencies to implement a method within four years for maintaining pavement marking retroreflectivity at or above minimum levels. Hence, the key objective of this study was to develop a simple tool for TxDOT and other Southern state and local agencies to help them comply with the new federal rule. To do so, pavement marking data from the National Transportation Product Evaluation Program (NTPEP) were retrieved and analyzed. Results indicated that the service life of standard water-borne paints varies significantly from 0 to 3.9 years according to the project conditions. Hence, a performance prediction model was developed with superior accuracy to predict the expected service life of standard waterborne paints based on the initial retroreflectivity value, traffic level, and marking color. This model can be used by TxDOT and other southern state agencies to determine the expected restriping time before the retroreflectivity drop below the minimum threshold, and hence, comply with the new federal rule.