Most countries solve that issue by separating the high speed rail lines from the land much better than you would bother with low speed rail. A mind boggling amount of infrastructure goes into separating the Shinkansen from the rest of the world. Hundreds of kilometers of it is raised up on bridges, the rest is inside tunnels or strongly fenced off by wire fences or concrete walls. No level crossings either.

I imagine part of the design of the front of the trains is also to minimize damage by deflecting impacts. Although I think the major design drive for their long noses is entering and exiting tunnels without creating sonic booms and air pressure issues for passengers.