What does the narrow structure sign mean?

This sign is posted on a two-way road before a bridge. What should you do as you approach it?

Slow down and keep right, because there is less room than usual for two vehicles

The structure is narrower than the road leading up to it, so the space beside you shrinks at the moment you meet oncoming traffic. Slowing before the bridge rather than on it is what leaves you an option if a wide vehicle is already coming through.

This sign is posted on a country road ahead of an old stone bridge. What should you do?

Slow down, look for oncoming traffic and be ready to give way at the narrow part

The structure is narrower than the road leading to it, so two vehicles may not pass each other comfortably on it. Slowing early lets you see whether anything is coming and lets you wait on the wide side, rather than meeting the other vehicle in the middle.

This sign is at the roadside on a two lane road, with an oncoming vehicle some way off. What should you do?

Adjust your speed so you are not alongside the other vehicle at the tightest point

The structure ahead is narrower than the road leading up to it, so the space beside you shrinks exactly where there is nowhere to go. Changing your speed early lets you meet the oncoming vehicle before or after the pinch instead of inside it. Watch for cyclists as well, because their room disappears first.

This sign appears on a country road where a bridge crosses a river ahead, and a wide truck is coming the other way. What is the safe plan?

Slow down, and if there is any doubt about the width, hold back and let the truck come through

The sign means the structure is tighter than the road leading up to it, so two wide vehicles meeting on it have nowhere to go sideways. Arriving slowly leaves you the option of waiting on the approach, where there is still room to wait. Racing for the bridge turns a decision you could have made calmly into one you cannot undo.

The structure ahead is narrower than the road, and an oncoming truck will reach it at about the same moment you do.

Ease off and let the truck through first, then take the structure with the lane to yourself

A narrow structure takes away the room you normally have to move inside your lane, and a truck passing close by adds a shove of moving air at the moment your options shrink. Giving up a few seconds keeps your escape space and lets you ride the structure without a large vehicle beside you.

This sign warns that the structure ahead is narrower than the road you are on. A truck is coming the other way and will meet you on it.

Slow before the structure and take a position on the side of your lane away from the truck

A narrow structure takes away the room a rider normally uses to move sideways, so the position and the speed both have to be chosen before you get on it. Sitting away from the oncoming side buys you distance from a wide vehicle that is closer to the centre than it looks. The very edge is worse than it sounds because that is where debris, broken pavement and the curb of the structure collect.