TRB’s Commercial Truck and Bus Safety Synthesis Program (CTBSSP) Synthesis 8: Commercial Motor Vehicle Driver Safety Belt Usage identifies and documents motivating factors that influence commercial motor vehicle (CMV) drivers in deciding whether to wear safety belts and research and practices that address CMV safety belt usage. It also offers a review of ergonomic and human engineering factors in the design and use of safety belts in CMVs as well as approaches to facilitate safety belt use by truck manufacturers.