"I don't understand by what you mean that they could be better lit, because they are. Our highways are lit and then they are even better lit because of the traffic that flows in them."

I mean street lamps are meant to light the road- so cars can see a pedestrian or dog so they are not run over.
Street light makes walking in the night easier and reduce crime.
Street lamps serve no purpose lighting the sky.
So, you should not be able to see the bright light of a street light from more than a few blocks away.
From a plane you should never see a street lamp- ever.
Nor should you ever see a street lamp looking at a city from miles away.

This is simple stuff. One could do much better than this.
But first let's do the simple stuff.

What meant by better lit, is getting closer to providing exactly the right amount of light needed in the right place and at the right time. This is a whole science of endless solutions and possibilities.

Example of high tech:
Philips Designs the 'Light Blossom,' an Intelligent Street Light Concept
"One solution to the urban lighting problem is a new concept called "Light Blossom," designed by Philips Electronics. Light Blossom is an intelligent LED lighting system that can provide bright light when it senses people walking nearby, and decrease its luminosity when people aren't around. The technology is also energy-efficient and operates off the grid, gathering solar and wind energy during the day to use for light at night."
http://www.physorg.com/news143438150.html

I'm promoting this particular device. It's just example how things could be done in future.