After reading that pilots are the safest drivers, I've made sure to always look around my car as I drive.
Hitting another car of the same size coming from the opposite side when each car is doing 35 mph is pretty similar to hitting a concrete wall at 35 mph. There is no 70 mph effect. The reason the pole would be safer is that it has some give. Lower acceleration = lower force.
Unfortunately, poles, especially old ones, do not have as much give as one would like, and large trees have basically none. Plus, their narrow aspect is a very bad thing to hit; cars are designed to collide with large, flat, wide objects and to crumple accordingly to wash off energy. Hitting an immoveable narrow object is outside this design consideration and cars have a nasty tendency to wrap around it.