Inspections of commercial vehicles reached an all-time high in West Virginia last year, with nearly 23,000 inspected.
The Public Service Commission's 42 inspectors concentrated on areas with high truck accident rates, including Interstates 64, 68, 77, 79 and 81.
Truck inspections have increased tenfold in recent years as West Virginia has received more federal funding. Last year, a $140,000 federal grant paid for overtime pay for truck inspectors.
Inspectors put 36% of the vehicles inspected out of service, mostly for bad brakes, and 12% of the drivers. A new heat-sensing device was used to help inspectors target trucks with potential brake problems.
West Virginia has also lowered speed limits and put in mandatory truck stopping areas on the state's most dangerous grades.