What does the no bicycles sign mean?

This sign is posted at the start of a road you are turning onto. What does it tell you?

Bicycles are not allowed on this road at all

The sign bans the bicycle from the road rather than setting conditions for it, so walking one along the shoulder is not the workaround it looks like. Roads are signed this way where the speed of the traffic leaves a cyclist no margin at all.

You are riding a bicycle and this sign faces you at the start of a bridge. What does it mean for you?

Bicycles are not allowed on this road, so you need another route

The sign bans bicycles from the road itself, usually because the lanes are narrow, the shoulder is missing or the traffic is too fast to share the space safely. There is normally a marked alternative nearby, and a driver should read the same sign as a reason not to expect cyclists past this point.

This sign is at the entrance to the road you are joining. What does it mean for how you drive there?

Bicycles are not allowed, though you still watch for riders who have strayed on

The sign bans bicycles, usually because the road is too fast or too narrow to share safely. It does not promise you that nobody will be riding there, so it changes what you expect rather than how carefully you look. A rider who has ended up on that road is in more danger than usual, not less.

You are riding a bicycle and reach this sign at the entrance to a road. What does it mean for you?

Bicycles are not allowed on this road, so you need another way round

The sign keeps bicycles off that road entirely, most often a bridge, a tunnel or an expressway where the difference in speed is too great. Getting off and pushing does not help, because the ban is on the road, not on riding. Look for the marked alternative, which is usually a parallel street or a path.

You are carrying a fare toward a bridge approach and reach this sign, with several cyclists still riding on the road just short of it. How should you drive here?

Expect riders to turn off or dismount at the sign and leave them room

The sign closes the road ahead to bicycles, which makes this approach the place where riders have to turn off or get down, not somewhere beyond it. A taxi building speed toward a bridge meets them exactly where they are changing direction and looking for the alternative route. Reading the sign as a clear road removes the caution the approach needs most.