How people chose to drive on a road is up to them.

The UK has signed up to international law, implemented as domestic law, not harm endangered species of wildlife. Doesn't matter if it's a cuddly bear or a slimy snail; that's the thing about laws, you either follow them or you're breaking them.

So yeah, snails, bats, and yes newts, they're protected by law. And some roads don't get built because of that.