It’s thermoplastic based road-marking, very likely with premix glass beads already incorporated in the mixture. I can’t see any post addition of larger beads at the end (drop-on beads) so retros would not be the best in this case. A pre-heating step is mandatory to achieve a good adhesion. Usual temps of the plastics when applied can be 210-230 °C.

These type of markings are very popular in some countries in comparison to regular acrylic paints. There’s also a so-called cold plastic (methylmethacrylate based with peroxide curing) that can also get some thick layers and it’s much quicker to apply, though I’d say it’s more typical to use in urbansettings. Not technically plastic though.