When looking at any risk, engineers are trained to grade them on two axes:
1. Probability of occurrence
2. Impact of occurrence
We obviously treat aircraft, because the impact of not doing so is very high, no matter what the probability of occurrence is. I'd argue that with trucks, if due only to the tens of millions of them on our roads every day, the probability of occurrence is extremely high.
Put otherwise, someone somewhere is getting a sheet of ice landing on their car, possibly thru their windshield. Obviously less newsworthy than a plane falling from the sky with 250 passengers aboard, but it's still a risk worthy of consideration or mitigation.