Well the truck and car lights are spot on - a steady 12V supply from a battery giving dead smooth 12VDC

The traffic lights on the other hand have proved to be a maintenance nightmare and more unreliable than the old incandescent bulbs.. they were from what i gather changed over as incandescent blew as they know the technology will get better.
I import LED downlights - compared to halogen these are bloody great - can run 8 off  3 X 2W LED from one 50W supply compared to one 50W halogen.
6W of LED can give the equivalent light output of just under 1 X 50W halogen - interestingly enough though 3X 2W LED pulls LESS current than a single 5W LED. In other words the extent that LED can go is a non linear equation.

LED;s are bloody great and will take over from incandescent... however they are not THE most energy efficient form of light - this still after over 100 years of steady service remains firmly in the pocket of neon, which is 3X more efficient than LED given the same power supply - if using standard iron core transformers then LED JUST beats neon for linear length, but not on light output.

Remember that LED is only 90% efficient once you have a steady 12V DC supply - you have to convert mains AC to 12V DC first and this is where BIG inefficiencies lie...

But for incandescent.. LED is the future by a long mile