Machine Learning–Based Framework for Prediction of Retroreflectivity Degradation of Pavement Markings across the US

Abstract

Pavement markings are essential traffic control devices that enhance safety for motorists during nighttime. Numerous statistical learning models have been developed in prior studies to predict the retroreflectivity of the markings, but the applicability of these models is questionable in terms of accuracy. The key objective of this study was to develop a machine learning–based framework that can be used by US transportation agencies to reliably predict the retroreflectivity of their pavement markings over a period of 3 years utilizing the initially measured retroreflectivity and other key project conditions. The random forest (RF) algorithm was used in this study to develop the proposed framework considering seven types of marking materials in three different US climate zones. A total of 49,632 transverse skip retroreflectivity measurements were retrieved from the National Transportation Product Evaluation Program (NTPEP) and 11 RF models were developed to sequentially predict retroreflectivity at different prediction horizons. The models were trained with randomly selected 80% of the total data points, and the remaining 20% data points were utilized for testing the predictive performance of the developed models. The RF models predicted the retroreflectivity with a superior level of accuracy (R2 ranging between 0.88 and 0.99) than the models proposed in prior studies. These models are expected to aid transportation agencies in reliably determining the effective service lives of their marking products.