Well TCP doesn't do collision avoidance, it's a link layer thing. And on Ethernet, it is collision detection on the shared medium. Wireless does avoidance due to the hidden terminal problem.
Neither of these models is really analogous to cars on the road.
But applying collision detection and exponential back off in road traffic is a "fun" thought experiment.
A more apt model would be critical sections and semaphores from concurrent programming. Which is named after a collision avoidance scheme used to control trains. And we all know how difficult concurrent programming can be. I don't want traffic with deadlocks, starvation, busy waiting or live locks.
I mean, heck. If it were that easy to start a unicorn...
But seriously - I am not saying its easy, I'm just surprised that we haven't made much (publicly known about/announced) efforts along these lines.
I mean, we have TCP down pretty good - if we are simply thinking of cars as packets, a lot of the math should exist to ensure collision-less delivery?