It’s actually none of the above. Specifically on limited access highways, FHWA now mandates the lines be laid into grooves that are milled just into the top surface of the asphalt; 80mil to be exact. The issue is rain water at this depth fills the groove just enough to create a mirror effect that obscures the paint by reflecting the light from headlights off the top of the water.

Voila, can’t see lines. FHWA is aware of the issue and ongoing testing with grooves of varying depths are still being tested to try to balance elimination of the issue with increased longevity to the epoxy resin paint with glass beads used as the final striping.

As for thermoplastic, it damages the pavement and can only be replaced by milling and overlaying then painting with epoxy.

None of it is an exact science.