Well, the lasers currently in use are approx. 2 mW at 905 nm. They become Class 1 due to the continuous scanning. If a laser beam were to become stuck pointing in one direction, as GP mentions, it becomes Class 3R.

And with the current limitations to stay in Class 1, range is 100m or less, so basically useless on a highway. There is a lot of work going on to find good tradeoffs in power and wavelength to give useful range while staying in Class 1.