30' or 5' same difference when it goes wrong. There are not too many people that will out run a crashing car even with a 30' head start. It all comes down to self preservation and making sure you have a out and never take your eyes off the cars. US, Mexico, all the same, people are people.Circling back to the question posted by the OP, the only effective method would be to hire enough security to establish a safety perimeter 30 feet away from the race course. Cost effective? Hell no, so it's never happening.
Kyle (^^) nailed it; calstyl2, too. People building booby traps and getting hit by race vehicles generally fall in the same profile: people with no civil values nor disregard for their own or other's safety that couldn't care less for off road as a sport.
The other option would be to go BLM on racing orgs down here, but it'd really suck. After typing this, a question came to mind in retrospective: Is it more important for me to have not-sucking races than the lives of those who don't care for their own? Well, food for thought.
Good point-When someone figures out how to put common sense into the general population we might stand a chance. It doesnt matter if it locals, spectators, or even CHASE crews! I was amazed at how many chase crews were actually parked too close to course and on the outside of turns! There was even one chase crew set up sitting in the middle of a chicane in their chairs under an ez up!
We cant point fingers at others if some of the even the race teams are not using logic.