When the surface crumbles away like this it makes the bike lane uncomfortable (and sometimes dangerous) to ride on. Bikes don’t have the massive tyres and suspension of vehicles to absorb the uneven surface.
Crumbling Bike Lanes

When the surface crumbles away like this it makes the bike lane uncomfortable (and sometimes dangerous) to ride on. Bikes don’t have the massive tyres and suspension of vehicles to absorb the uneven surface.