The Commercial Vehicle Safety Alliance held its annual, unannounced brake check day on May 4, inspecting 6,128 vehicles in the U.S. and Canada.

Out of those vehicles, 12.4% were placed out of service with brake violations and 13.9% were placed out of service for other violations. Brake-related violations typically make up the bulk of out-of-service violations, according to the CVSA.

Improperly installed or poorly maintained brake systems pose a serious risk to driver and public safety by reducing braking capacity and increasing stopping distances in trucks and buses, CVSA noted.

In this inspection, anti-lock braking systems were also a focus, with most inspections recording the number of vehicles with ABS as well as the number of ABS violations that were recorded. It was found that most vehicles were equipped with ABS but some had fault codes or non-functioning ABS lamps. Trailers requiring ABS were twice as likely to exhibit ABS violations as straight trucks or tractors requiring ABS.

Hydraulic-braked, ABS-required trucks had slightly more violations than air-braked trucks requiring ABS at 9.8% to 9.6% respectively. Trailers requiring ABS exhibited ABS violations at a rate of 19.8%.

CVSA’s next Operation Airbrake event is Brake Safety Week, Sept. 11-17. It is a week-long brake safety campaign aimed at improving commercial motor vehicle brake safety through education and enforcement.