wierd. disable your graphics mods if you have any, seems like obvious solution ikr.
I see so many reviews, people say it's crashing and stuff. I have 50+ mods (mainly sounds and truck overhauls) and it works perfectly fine - no crashes, no glitches.

Thanks for the tip! I've tried verifying and unfortunately the issue still occurs. (I'm currently playing vanilla with no mods). Can't figure out what's causing it, it happens quite sporadically.

It does disappear after a few seconds, although by then I've normally driven off the road!

This looks like an issue caused either by corrupted files or incompatible mods. Try to verify the integrity of your files on Steam and make sure all your mods (if you use any) are compatible with update 1.48.5. I hope this helps.