In the United Kingdom, what does a blue circular sign with a white upward arrow require drivers to do?

In the United Kingdom, a blue circular sign with a white upward arrow requires drivers to proceed straight ahead.

This is a mandatory-direction sign, not a warning or an optional route suggestion. The blue circle tells road users that the instruction is compulsory, while the white arrow shows the permitted direction of travel. Drivers must continue ahead where the sign applies, unless another instruction or road condition makes that impossible.

The sign is commonly used at traffic islands, junction approaches, and other places where turning movements need to be controlled. It helps separate mandatory instructions from advisory information, which is often shown on rectangular signs.

A common mix-up is treating every arrow sign as a direction to a destination. A blue circular arrow instead regulates movement at that location. Left- and right-pointing versions impose the corresponding turn, while a red-bordered circular sign with an arrow crossed out prohibits that movement.