Complex behaviors are difficult to evolve. There is unlikely to be a "stay away from roads" allele, while a "no tusks" allele was already in the elephant population.

If they live in an area where there are lots of roads everywhere, completely avoiding them may actually be maladaptive, as not every road crossing results in a fatality and they could well be trapped in a small area without it.

If they live in an area without many roads it probably doesn't really matter.

Here in Seoul, the feral cats seem to have evolved a phenotype to be afraid of open spaces.The result is that they cross roads very quickly.

And possums too

How would you know if they have been? As the human population shoots up massively, car-miles have increased enormously over the past century, and rural areas become denser, the number of deer-car accidents would skyrocket even if they have successfully been evolving to reduce risk.