You may think that they are oblivious, sitting high above the road in the cabs of their semitrucks. But it turns out that truck drivers are actually very aware of the hazards they face out on the highway.

According to a survey done on a social media site for truckers, in response to the question of the worst weather conditions in which to drive their big rigs, this was how the truck drivers ranked them.

1. Freezing rain

Nearly 63% of the surveyed truckers found that this hazard made it the most difficult to maintain control of their semitrucks. Because of the unpredictability of the road conditions during spates of freezing rain, jackknifing poses a real risk to them and others sharing the highway with them.

2. Heavy snowfall

Almost 20% of truck drivers listed heavy snow as the next worse condition for driving. Even with chains and salted or sanded highways, if the conditions get really bad, they could wind up stuck in a drift. It’s better to pull over and wait it out than to get pulled from a ditch and potentially lose your load.

3. Fog

In third place at close to 15% was driving in fog. Most trucks can cut right through patchy fog, but it’s the dense and large fog banks that reduce visibility to zero that they dread.

When it is very foggy, it’s best for truckers and passenger vehicles to get off the road entirely. Pulling over onto the shoulder is dicey because their tail lights can confuse other motorists who could then slam into them.

4. High winds

Rounding out the list in the number four spot is high winds. Almost 4% of truckers said they dreaded driving in high winds. The high profile of semitrucks coupled with strong crosswinds can be enough to topple a truck right over on the highway.

If you get injured in an accident with a large commercial semitruck, you may need to file a claim for damages in order to be compensation for your losses.