I watched a science program about how roads were causing genetic problems with some species somewhere in Canada, I think. They built terrain bridges over the highways in key areas which seemed to provide a reasonable solution for that particular issue. Just fifty other problems to go. :-/
Yes. Similar issiues exist wherever there is long border fences/ walls.
There has been more pressure to build raised animal crossings over highways and roadsways in the last couple decades but the roadkill is truly brutal. We definitely need more of them, at that though just reducing the amount of vehicles on the road would be great too.
Auto and oil industry have too much political influence as it stands. We have to reduce their significance to make progress.