When the 4449 went east out of the Los Angeles basin, I cannot remember the occasion -- maybe the train to New Orleans or the American Freedom Train or both -- the California Highway Patrol (CHP) was prepared. They had an officer with radio riding at the open baggage door of the crew car to watch for the real foolish drivers and report them to ground units. I think they also had a helicopter out.
Also I understand, that east of Colton where the railroad goes through San Timoteo Canyon and is paralleled by a curvy 2-lane road, the CHP made a temporary closure and did not allow traffic moving against the direction of the train. Better to inconvenience a few unknowing drivers than have a head-on collision on the road.
Over the years, I have been out on train chases with a-now-deceased, experienced chaser/photographer. I recall when we followed the Royal Hudson over Tehachapi after it visited Los Angeles with a visit B.C. promotional train. The ascent out of Mojave was nerve racking as both railfans and other drivers paced the engine. When we got to the downgrade toward Bakersfield things got better for us. Often we would be the last to arrive at a good photo location and pop out of the car, get our photos from a side without getting into anyone's photo, then hurry back to the car and be one of the first out. We repeated this at several locations.
The fun when young.
BN