Actually, our traffic laws are made for the lowest common denominator driver.
And traffic lights are, even in todays computer automated society, arbitrary in their function. That is why, for more and more people, they are optional - assuming there are no cops around.
I like your minimum price analogy.
I oversimplified the speed limit discussion, true.
The min price analogy is not mine. If you've ever endured Econ 101, it's the same graphs for a minimum price as it is for a minimum wage. Supply curve, demand curve, price floor.
Price floor=surplus, price ceiling=shortage.
So, with a price floor for wages, there are way too many people who want a job compared to job suppliers who want to supply a job at that price.
My favorite analogy, though, is the Spongebob analogy. Why would you make Mr. Krabs fire that great little sponge?