I think your last paragraph is the key one. AFAIK in the US a lot less is regulated on a federal level. Like in Oregon you'll rarely see reflectors on the lane markings whereas they are omnipresent in some other states.
What are these lane markings you speak of? I must tell our local street department, they will be amazed to hear of it.
The lack of reflectivity of lane markings in North Carolina made night driving in the rain on the multi-lane roads around Raleigh quite a demanding task.