Get off the interstate if you can
The best place to break down is a parking lot. If the truck is losing power, showing a warning light, or making a new noise, use whatever it has left to reach somewhere safe: an exit, a truck stop, a wide shoulder, or a yard.
- Signal early, slow down gradually, and move as far right as you can.
- Don’t stop on a bridge, on a ramp, in an interchange, or just past a curve or hill where drivers can’t see you coming.
- Don’t park over tall, dry grass or leaves. A hot exhaust or DPF can start a fire.
- If a red stop-engine lamp, low oil pressure, or high coolant temperature warning comes on, stop as soon as it’s safe and shut the engine down.
If the truck stops in a travel lane and you can’t move it, turn on your flashers and call 911 before anything else.
Flashers on, triangles out
Federal rules (49 CFR 392.22) require the driver of a stopped commercial vehicle to turn on the hazard flashers right away and keep them on until warning devices are out. The triangles have to go out as soon as possible, and within 10 minutes of stopping. Put on a high-visibility vest before you walk along the truck.
Where the three triangles go depends on the road:
| Road type | Where the three triangles go |
|---|---|
| Two-lane, two-way road | One about 10 feet (4 paces) from the truck on the traffic side, one about 100 feet (40 paces) behind, and one about 100 feet ahead |
| Divided highway or one-way road | All three behind the truck, facing approaching traffic: about 10, 100, and 200 feet (4, 40, and 80 paces) |
| Hill, curve, or other obstruction | Move the warning on the approach side farther back — between 100 and 500 feet — so drivers see it in time |
East Tennessee has plenty of hills and curves, even on the interstates. When in doubt, put that farthest triangle farther back.
Call, and have these answers ready
Once you and the truck are as safe as you can make it, call. If you drive for a carrier, follow its breakdown procedure first — many fleets want you to call their breakdown line, which can then approve a local mechanic.
These details make the difference between a one-trip fix and a wasted trip:
- Exact location. Interstate, direction, and nearest exit or mile marker — or the truck stop, yard, or business name. Send a map pin if you can.
- Truck details. Year, make, model, and engine. Trailer type if the problem is on the trailer.
- Symptoms. Warning lights and codes, what happened right before, and anything you heard, saw, or smelled.
- Current state. Will it start? Is it derated? Are the brakes locked? Is anything leaking?
- Load. Loaded or empty, hazmat class if placarded, and reefer setpoint if it applies.
- Contact. A callback number for whoever is with the truck.
Around Knoxville, call Knoxville Mobile Diesel at (865) 500-4283 — dispatch is open 24 hours a day.
Wait safely
- Get away from traffic. If it’s safe, wait behind a guardrail or well off the road on the side away from traffic. Trucks stopped on shoulders get hit.
- Don’t stand between the truck and traffic, or directly behind the trailer.
- Dress for the weather. A January wait on the shoulder of I-40 gets cold fast. In summer, drink water and find shade.
- Watch for fire. Smoke, a burning smell, or leaking fuel means get away from the truck and call 911.
- Don’t try repairs next to a live lane. Leave that to a mechanic with lighting and equipment.
When the mechanic gets there
Tell the mechanic what you told dispatch, plus anything that’s changed. Have the keys, your paperwork, and any gate or yard access info ready. Before the truck leaves, ask what was found, what was fixed, and whether anything still needs a shop soon. Keep the itemized invoice with your maintenance records.
Knoxville-area tips
- On the I-40/I-75 overlap through West Knoxville, shoulders are busy and traffic is heavy. If you can reach Watt Road (Exit 369) or another exit, do it.
- Hauling hazmat? You’re required to use I-640 around downtown. If you stop, tell dispatch the hazard class up front.
- Know which interstate you’re on. I-75 uses I-40 exit numbers through West Knoxville and I-640 numbers to Sharps Gap. Give dispatch the exit number you see on the sign.
- Before the mountains, check coolant, belts, and brakes — whether you’re heading to Jellico on I-75, the plateau on I-40 west, or the Pigeon River Gorge on I-40 east. See our mountain grades and winter guide.
General information only. This guide is written for drivers and dispatchers working around Knoxville and East Tennessee. Rules change and every truck is different — follow your carrier's procedures, current FMCSA regulations, and the directions of the Tennessee Highway Patrol or other officers on scene.