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ODOT Seatbelt Study

Dan Franz
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June 25, 2024

Since 2017, Quality Counts has been contracted by Oregon DOT’s Transportation & Safety Division to collect seatbelt utilization rates at 180 sites statewide.

The project is part of a national reporting requirement by the National Highway Transportation Safety Administration (NHTSA) in order to qualify for federal funding. Each state must propose a survey methodology which complies with NHTSA’s statistical requirements, and the results of the collection certify the state as a “high use” state if it has higher than 90% compliance with seatbelt laws.

Seatbelt observations are collected at each of the 180 sites by an onsite observer, during daylight hours (generally 7am – 7pm). Each site is observed for 40 minutes, with an additional 15m vehicle volume count taken if the site is located along a highway. Observers determine if the driver and passenger in a given vehicle are wearing their seatbelts, and record it with a set of handheld clickers which are later copied onto a paper record sheet. A training session for all employees, as well as auditing 5% of the sites collected, is included in the contract for QA purposes.

The project contained many unique managerial challenges. The most difficult of these is that while the 180 sites remain the same for a three-year period, the collection must be randomized. Within a given geographic cluster, QC must randomize which site is to be the first collected, what day of the week the cluster should start collection on, and what time of day that site should be collected. This can create problems if the first site in a cluster starts at 7:15 AM and is five or six hours away from the office, or create extra travel days if a cluster doesn’t start its first site until 5 PM!  Because the start site changes every year, the route planning and optimization for each cluster has to be redone from scratch each time. We are additionally required to audit both 5% of sites, and every technician participating, and our auditors are kept hopping trying to fulfill this requirement – clusters range as far south as Klamath Falls (six hours away from Portland) and as far east as Ontario (7.5 hours away).

Because all collection must occur within a three-week window, and most clusters involve multiple overnight trips, it can be a logistical challenge to fit everything in, particularly if the randomization results in multiple clusters having to start on the same weekday. Close contact is required with our technicians – their routes are carefully planned, and can be upended if a given site is under construction and a replacement site has to be found on the fly to maintain the schedule.

For more information on seatbelt studies contact Dan Franz at dfranz@qualitycounts.net

WRITTEN BY
Dan Franz
Dan Franz has supervised numerous contracts including aggregate annual tube counts of more than 3,000 locations. In addition, he directly manages specialized projects where new approaches and dynamic methods are utilized. Dan joined QC as a Field Technician in 2007 – deploying and collecting traffic data collection equipment and downloading data sets. Today, he oversees those same operations and manages traffic data collection contracts throughout the West Coast and nationwide.