Federal Rules on Impaired Drivers, Truck Markings and Hazmat Coverage
Alcohol and the four-hour rule
A commercial driver may not use alcohol within 4 hours before going on duty, may not have any measured alcohol concentration while on duty, and a carrier may not let a driver work if the driver appears to have been drinking in that window (49 CFR 392.5).
Drugs and impairing medication
Drivers may not be on duty while using or under the influence of Schedule I drugs, amphetamines, narcotics or any substance that makes driving unsafe, and carriers may not permit it (49 CFR 392.4). A prescription is an exception only when a medical practitioner has advised that it will not affect safe driving.
Identifying the carrier from the truck
A commercial vehicle must display the operating carrier's name and its USDOT number on both sides, legible from 50 feet, and a leased truck showing another company's name must add “operated by” with the carrier's details (49 CFR 390.21). A photo of the door is often how the responsible company is found.
Higher limits for hazardous loads
Carriers hauling general freight interstate must carry at least $750,000 in liability coverage, and hazardous materials require more: $1,000,000 for many hazmat loads and $5,000,000 for certain bulk hazardous substances (49 CFR 387.9). Tankers on I-15 and I-215 fall in those higher tiers. Read our Utah truck accident claims guide for more.
If the truck leaves the scene
When a truck causes a crash and drives on, your uninsured motorist coverage may pay. If it never touched you, Utah Code § 31A-22-305(6) requires clear and convincing proof beyond your own testimony that it existed, so capture any name or number you saw on the door.