Green Driving?

Last evening driving to Atlanta for the first time in about ten years, it struck me that about a fourth of society even knows what Green/Environmental issues are about.
While on interstate 20 our average speed was about 72 to 75 mph other cars were passing us like we were sitting still. Once we hit Atlanta turning onto 285 north with signs clearly posted at 55 & 60 mph again cars were whizzing by us. One driver entered onto 285 and immediately went from the entrance ramp to the far left lane.
The problem is not just the reckless, thoughtless and oblivious to rules driving habits, there is no attempt to be aware, speed uses more fuel. Until drivers are penalized for careless driving and ignoring the law, we can not possibly save fuel.
A small car scares me beyond belief even with a fuel efficient vehicle, I want to go smaller. Can anyone imagine the impact of a semi tractor trailer with a SMART car or even a huge SUV? The state patrol and police have budgets cut and could not be every where. Where does social responsibility come into play, I know it is all very rhetorical.