The 'opening or swing bridge ahead' warning sign informs drivers that the road crosses a waterway via a movable bridge that opens to allow boat traffic through.
When activated, red flashing traffic signals or barriers will stop vehicle traffic until the bridge closes again.
What this sign means
This sign shows a bridge deck tilting upwards inside a red warning triangle. It alerts drivers that traffic may be held up unexpectedly by river traffic.
It is often accompanied by supplementary signals such as twin red flashing lights or automatic lifting barriers.
- Pictogram depicting an opening bridge span
- Found near river basins, ports, and canal locks
- May feature warning lights or distance indicators below
What to do when you see it
Moderate your speed and watch for warning lights, wig-wag signals, or lowering barriers ahead.
- Be ready to stop if red light signals begin flashing
- Switch off your engine if queued for a prolonged period
- Never attempt to drive past lowering barriers or amber lights
How this sign is tested
Theory questions focus on driver behaviour at movable bridges and the correct response to twin red flashing light signals.
- Understanding action required when red lights flash
- Fuel conservation advice like switching off engines while waiting
- Recognising bridge warning symbols in visual questions
Common mistakes
Trying to speed up to cross the bridge before barriers lower, or failing to turn off the engine during extended bridge openings.
Test yourself on this one
Road and traffic signs is the biggest category in the question bank with 102 questions, and signs turn up inside other categories too. Work through them free, no sign-up needed.
Practise road sign questionsFrequently asked questions
What lights are used at an opening bridge?
Twin red flashing lights (wig-wag signals) are used to stop traffic when the bridge is about to open.
What should I do if the bridge lights start flashing as I approach?
You must stop behind the stop line unless it is unsafe to do so.
Should I turn off my engine while waiting?
Yes, if you expect to be stopped for more than a minute, turn off your engine to cut emissions and conserve fuel.