There was an national effort to bring awareness of the situation to the forefront and things started improving. Governments aren't supposed to spend precious tax dollars on things that enrich the lives of working class folks. If the people are dumb enough to throw trash out their cars, let them wallow in it. The moneyed interests don't profit from picking up trash off the streets. It is just human nature for a some folks to think that they don't have to comply to society's norms unless they are forced into it.
Some folks are just that way.
I think police and judges and jails are a last resort to cope with extreme behaviors, but not littering. I pick up an occasional beer can from my front yard. I reckon that some nocturnal motorist has rationalized he would rather risk being caught littering on a dark street than drive around with open containers in his car. We still have programs in our society to discourage drunk driving. I suppose the beer cans in my yard are evidence that my drunk comrade is aware he is engaging in risky behavior.