Black Ice on East Tennessee Bridges: Getting Out of the Ditch

East Tennessee does not get long deep freezes so much as repeated swings across the freezing point, and that pattern produces more black ice than a steadily cold climate does. If you have gone off the road, stay put, keep your belt on if traffic is still moving, and call Knoxville Towing at (865) 606-6676.

Why bridges catch people

A road surface is warmed from underneath by the ground, which holds heat well and releases it slowly. A bridge deck has cold air on both sides, so it reaches freezing sooner and stays frozen longer than the approaches on either end.

The result is a driver traveling on wet pavement who crosses onto a frozen deck with no visual warning. Black ice is not black; it is transparent, and it looks exactly like wet asphalt at night. The first indication is usually the steering going light.

Overpasses, shaded curves, and low spots near water behave the same way. In this region the Tennessee River crossings and the bridges on the ridge roads are the reliable offenders, and they ice when the air temperature is still above freezing because the deck itself is colder than the air.

The moment it starts

Come off the accelerator without braking hard. Locking the wheels on ice removes any steering you had left, and modern stability systems work far better when they are not fighting a panicked input.

Steer where you want the vehicle to go and keep the movements small. Large corrections on ice produce a pendulum that ends in a spin, and most single-vehicle winter wrecks here are the second or third correction rather than the first slide.

Once you are off the pavement, the priority order is people, then position, then the vehicle. Nothing about the car matters until everyone is accounted for.

Stay in the vehicle, usually

This is the opposite of the advice for a breakdown on a dry interstate shoulder, and the reason is that the same ice that put you in the ditch is under everyone else's tires too. A person standing outside a vehicle beside an icy road is exposed to drivers who cannot stop.

Remain belted, keep the hazards on, and stay on the phone with us. If the vehicle is in a position where it could be struck and you can reach genuinely protected ground away from the road, that is the exception — but a ditch below the road surface is often safer than the shoulder above it.

Run the engine sparingly for heat and check that snow or mud has not blocked the exhaust. Carbon monoxide with a plugged tailpipe is a real hazard in a stopped vehicle, and it is a quiet one.

What recovery involves

Getting a vehicle out of a ditch is a winching operation and the ground conditions dictate how it goes. Frozen ground gives a truck something to work against; mud beneath a frozen crust does not, and the truck itself has to be anchored before pulling.

Damage assessment matters before the vehicle is driven away. A slide into a ditch commonly bends steering components or cracks a wheel, and a car that appears fine can have an alignment far enough out to be unsafe at speed. That is a judgment call we will make honestly, including when the answer is that it should go on the bed rather than drive home.

Multiple vehicles in the same location happen constantly on ice, since the conditions that caught you catch the next driver at the same spot. Expect that we may be working a queue, and tell us if anyone in your vehicle is injured or if children or pets are aboard.

Reducing the odds

Tires do more than anything else. Tread depth and rubber compound are what actually contact the road, and all-wheel drive helps you accelerate while doing nothing for stopping or steering on ice.

Increase following distance well beyond what feels necessary and slow before a bridge rather than on it. Braking on the deck is what turns a manageable crossing into a spin.

Refreezing is the pattern that catches people twice

The characteristic East Tennessee sequence is a day above freezing that melts everything, followed by a clear night that drops the surface temperature well below the air temperature. Meltwater that ran across the road at four in the afternoon is ice at six in the morning, on a day when the forecast never mentioned snow.

Roads that were treated for a previous event are not necessarily protected, since brine gets diluted by melt and washes off. Shaded curves hold ice for days after open stretches have cleared, and the difference between the two can be a hundred yards apart on the same road.

Treat any morning after a thaw as an ice morning, particularly on bridges, ramps, and north-facing slopes.

We respond throughout Knoxville, Clinton, Oak Ridge, Lenoir City, and the surrounding counties. Call (865) 606-6676.