Estimating motorcycle miles travelled from state vehicle inspection records
Subtype: Final report
Author(s): Kirley, Bevan B.; Wang, Yudan; Foss, Robert D.; Harrell, Stephanie; Goodwin, Arthur H.
Publisher: National Highway Safety Transportation Administration
Publication Date: May-2022
Number: DOT HS 813 288
Address: Washington, DC
Abstract: Estimating vehicle exposure is difficult for any type of vehicle, and motorcycles are no exception. As motorcyclevehicle miles traveled (VMT) is based on traffic counts of sampled roadways supplemented with trafficmodeling, a long-standing challenge of measuring motorcycle exposure is due to motorcycle characteristics interms of size and type (smaller, lighter, single-axis) and use (recreational and weekend trips). This study soughtto improve our understanding of this issue by examining use of motorcycle odometer readings as measures ofVMT. The study used odometer data to calculate motorcycle mileage. The odometer data were part of motorcyclesafety inspection records provided by three States — Hawaii, from 2013 to 2016; North Carolina, from 2012 to2016; and Virginia, from 2012 to 2017. Mileage was computed for motorcycles that had more than one inspectionrecord. The results showed that mean annual mileage per motorcycle was consistent year-to-year for the periods studied,and motorcycles on average were ridden about 2,000 miles each year. This distance is lower than the mileagereported in self-report studies, suggesting that self-reports may be overestimations. Also, the annual motorcyclemileage was skewed, with a large proportion of motorcycles having been ridden for very few miles each year.The current study suggests that inspection records are valuable for revealing patterns of use, as they are a directmeasure of distance ridden. The information in this report is presented to share research findings; it is not arecommendation to use this strategy for computing VMT. There are signification limitations to using odometer-based readings from inspection records to calculate VMT. First, this type of odometer data is not widelyavailable, as few States require motorcycle safety inspections. Second, thousands of inspection records used inthis study had missing or erroneous odometer data. Third, interpretation of odometer-based VMT is challengingbecause inspected motorcycles may have mileage accrued out-of-State, thereby limiting conclusions about State-based VMT.