[salik_syed]

Interesting tidbit: The way we did this on the Stanford DARPA Urban Challenge vehicle was to use the intensity of the returned LIDAR signal ... the little reflective markers between white lane paint are actually covered using a retro-reflective coating. You can get extremely good detection rates. It's much more of a hack :)

[cbhl]

That's cool, but the little reflective markers don't get used in places that get snow (like Canada) because of snow plows.

[lttlrck]

Recessed markers are becoming increasingly common

https://www.azdot.gov/mobile/media/blog/posts/2013/01/25/tra...

Edit: anecdotally, in the NE US.

[sanswork]

The Toronto area had them everywhere last time I was there.