Louisville, Kentucky
Truck driving rules exist because an 80,000-pound rig needs more room, more time and a rested, sober driver. When a trucker or trucking company breaks those rules and someone gets hurt, the violation can be strong evidence of fault. Here are straight answers to the questions people ask most about truck driving rules in Kentucky: hours of service, drug and alcohol testing, the left-lane rule, following distance and no-zones.
Federal rules come from the Federal Motor Carrier Safety Administration (FMCSA). Kentucky adds its own traffic laws.
Key takeaways
Under 49 CFR 395.3, a driver of a property-carrying truck:
Electronic logging devices record driving time, and the carrier must keep those records. Violations are a common sign of truck driver fatigue.
Yes. Commercial drivers are tested before hiring, at random, on reasonable suspicion and after certain crashes (49 CFR Part 382). Under 49 CFR 382.303, the employer must test the driver for alcohol and drugs after any crash involving a death. After a crash where someone was treated away from the scene or a vehicle had to be towed, testing is required if the driver gets a moving-violation citation. Alcohol tests are due within 8 hours, drug tests within 32 hours.
Missing or late tests, and the driver's record in FMCSA's Drug and Alcohol Clearinghouse, can matter in a lawsuit. See our guide to FMCSA safety records.
On a road with three or more marked lanes going one direction, Kentucky law says a truck tractor, trailer or semitrailer may not use the leftmost lane except when entering or leaving the highway, yielding to merging traffic, or when conditions make the right or center lanes unsafe (KRS 189.340(7)(c)). On two-lane-each-way interstates, the general rule is to keep right except to pass.
Outside a business or residential district, a truck, semitrailer truck or bus may not follow within 250 feet of another vehicle, except when passing (KRS 189.340(9)(b)). Tailgating trucks cause many rear-end crashes, and a truck's black box can show its speed and following distance. See speeding truck accidents.
No-zones are a truck's blind spots: directly in front, directly behind, and along both sides, especially the right. Drivers of passenger cars are taught to avoid lingering there. But a truck driver still has a duty to check mirrors and make sure a lane is clear before changing lanes or turning, so a blind spot isn't an excuse for a sideswipe or a underride crash.
Ask for a lawyer to send a preservation letter right away, so logbook data, test results and black box data aren't lost. Most Kentucky truck crash injury claims must be filed within two years of the crash or the last PIP payment (KRS 304.39-230(6)). See our truck wreck lawyer page.
Up to 11 hours of driving after 10 hours off duty, and no driving after the 14th hour on duty, under 49 CFR 395.3.
After any fatal crash, yes. After an injury or tow-away crash, testing is required if the driver gets a moving-violation citation (49 CFR 382.303).
Not on roads with three or more lanes in one direction, except to enter or leave the highway, yield to merging traffic, or when the other lanes are unsafe (KRS 189.340(7)(c)).
At least 250 feet outside business and residential districts, unless passing (KRS 189.340(9)(b)).
We'll lock down the logs, test results and black box data before they're gone. Free case evaluation. Get a free case evaluation or call (502) 931-6788. No fee unless we win.
This page is general information about Kentucky law as of October 2026, not legal advice.
