These tunnel-cleaning trucks are immensely satisfying to watch

Some YouTube rabbit holes are worth the trip, like a foray into the genre of tunnel-cleaning trucks. It's next-level powerwashing porn.

These promo videos invariably have the best music tracks, too:

Check out the high drama as this tunnel gets a scrubbin':

It even makes washing solar panels awesome:

This one has the best before and after:

Camion lavage tunnels (YouTube / Colas Suisse)