Not much thicker than a piece of paper.

 

I’ve always found it amazing that a very thin strip of paint along the center of the road can keep two speeding cars from hitting each other head-on.

The odds are not really in your favor.  Many things enter into the equation.  Mechanical malfunctions with either vehicle, visual distractions, sudden appearance of animals, mental exhaustion or fatigue, cell phone distractions, children in the car with you, night with its on-coming headlights, or potholes, and don't forget blinding sunlight.

It is amazing we get from here to there.  Now technology wants to remove the human factor with self-driving cars.  This gives us an entirely new set of possible failures like, a programming glitch, a failed computer chip, an errant spark, or driving through a puddle and splashing water into the electronics.  Not to mention, removing the human factor also takes away any possibility of sound judgement, choice and reflex.  Never mind, sound judgement went out the window when you bought the car.

 

As always, opposing views are always welcome.