Mobile Retroreflectivity Best Practices Handbook

This handbook documents best practices related to proper use of the mobile retroreflectometer, sampling of sites for data collection, and handling of mobile retroreflectivity data. The best practices described in this handbook are derived from the results of Texas Department of Transportation (TxDOT) Project 0-5656 and the author’s observation in using the mobile retroreflectometer. The first part of the handbook provides information on sampling of pavement markings, periodic data quality checks, and data file naming conventions. The sampling procedure described here provides a systematic way of reducing the number of samples under a constrained budget. File naming conventions suggested in this handbook will be helpful in automating mobile retroreflectivity data handling and analysis. The second section of the handbook provides information on equipment required to calibrate the mobile retroreflectometer and collect the data. This handbook also describes the best practices for initial setup and calibration of the mobile retroreflectometer and calibration checks. Since several factors change as data are being collected, best practices for accounting for changes in variables, such as variations in vehicle speed and operating temperature, etc., are described. The final section pertains to best practices in data handling and suggested analysis of mobile data. This handbook elaborates on the consistency of data file headers and quality checking of data. A prototype of automation for data analysis is demonstrated that will prove handy in dealing with large amounts of mobile data.