Project: #16 Analysis of Effects of Tire Tread Deterioration on Safety Impacts from Analysis of Inspection Data Progress Report - Reporting Period Ending: Sept. 30, 2017 Principal Investigator: H. Scott Matthews Status: Active Start Date: Jan. 1, 2017 End Date: Aug. 31, 2018 Research Type: Applied Grant Type: Research Grant Program: UTC FAST Act Grant Cycle: 2017 TSET UTC Progress Report (Last Updated: Oct. 5, 2017, 10:02 a.m.) % Project Completed to Date: 80 % Grant Award Expended: 55 % Match Expended & Document: 50 USDOT Requirements Anticipated Research Outcomes Over the course of this one year project, we anticipate developing vehicle-level deterioration rates for vehicles. We have developed algorithms and data analytics that can be shared with various stakeholders, and to develop messaging for consumers that educates them on the issues of safety as related to tires. We seek to: * Estimate the deterioration rates of tire tread in all passenger vehicles in Pennsylvania over the past 10 years. * Estimate the percent of vehicles in the fleet that are driving with unsafe tires (as defined by the inspection threshold of 2/32") at time periods after the most recent inspection * Estimate the percent of vehicles that wait all the way until the next annual inspection to get tires replaced. The results will be created through data analytic methods, using Python and R programming. Anticipated Impacts We have been prioritizing work on the methods, but have shared results with several stakeholder groups to date. We have already presented interim results to attendees at national and PA conferences since May 2017 (see presentation details below). We also seek, when done, to open a dialogue with PennDOT officials about altering the tire tread depth thresholds given modern use of vehicles (10k VMT per year) and given the knowledge of sizable fractions of the fleet driving with unsafe tires. We hope to help them consider modifications of the current thresholds which anticipate consumer behavior. Did research results confirm or change practice? Not yet. Will update as available. Web Links Not Applicable Issues We have not experienced any significant issues in this project. Accomplishments We have already created initial estimates of the deterioration rates of tire tread in all passenger vehicles in Pennsylvania over the past 10 years. We estimate that the rate is 0.2 inches per 1000 miles, or 2/32" per 10,000 VMT. We have also begun to create the 'policy model' that considers the risk associated with the current tire tread inspection threshold of 2/32", to be able to consider the percentage of vehicles that meet the tread depth requirement at the time of inspection, but that would be expected to "fail an inspection" before the next annual inspection. Our current estimates are that about 25% of vehicles fall into this category. Further, we have created initial estimates of the percentages of vehicles with questionable tires that wait until the time of inspection to replace their old tires, which causes serious safety issues in PA.