Diversion route signs: the yellow symbols
Updated •6 min read
Diversion route signs are yellow signs with black symbols or black text that guide you round a closed road. When a road is shut, a temporary sign tells you which symbol to follow, and you follow that same symbol on each sign until you are back on your route.
The Highway Code shows two kinds: four "Symbols showing emergency diversion route for motorway and other main road traffic" (a square, a triangle, a diamond and a circle), and a yellow "Diversion route" sign with a place name and an arrow (gov.uk: traffic signs). Both sit among the direction signs, because they show you where to go rather than give an order.
The diversion signs at a glance
| Sign | What it looks like | When it is used | Our sign page |
|---|---|---|---|
| Emergency diversion symbol | Black square, triangle, diamond or circle on yellow | A motorway or main road is closed in an emergency | square, triangle, diamond, circle |
| Diversion route sign | Yellow sign with black border, place name and arrow | Points the way along a diversion | diversion route |
| Temporary diversion signs | Yellow temporary signs | A road is closed for works or other planned reasons | Shown in Know your traffic signs |
The descriptions come from the Department for Transport's Know your traffic signs, chapter "Direction signs on all-purpose roads", section "Signs for traffic diversions" (gov.uk: Know your traffic signs, direction signs).
What Know your traffic signs says
The section on traffic diversions is short, and every word is useful. It begins: "Where, in an emergency, it is necessary to close a section of motorway or other main road to traffic, a temporary sign may advise drivers to follow a diversion route."
It goes on: "To help drivers navigate the route, black symbols on yellow patches may be permanently displayed on existing direction signs, including motorway signs." So you may already pass these yellow patches every day without noticing them, because they stay on the signs when no diversion is running.
On ordinary roads the symbols can stand alone: "On all-purpose roads, the symbols may be used on separate signs with yellow backgrounds." The guide also says the symbol on a sign "may be replaced by route numbers".
Finally, it separates emergencies from planned closures: "Temporary diversion signs may be required when a road is closed for reasons other than an emergency, e.g. to carry out works."
How to follow a diversion
- Read the temporary sign before the closure. It tells you to follow a diversion and shows the symbol, or a route number, for your route.
- Remember the shape. If the sign says follow the triangle, look for the black triangle on a yellow patch at each junction, beside the road number you should take.
- Ignore the other shapes. A square, diamond or circle on the same sign belongs to a different diversion.
- Keep following it until the signs end. Then carry on with your journey, rejoining your route.
Know your traffic signs shows diversion symbols "alongside the road number of the route that drivers should follow" on the direction signs. Gov.uk does not give each shape a fixed meaning, so follow the one the temporary sign names for your closure.
Diversions, road works and closures
A diversion for planned works usually comes with road works signs too. Rule 288 says to "Observe all signs" at road works, that "You MUST NOT exceed any temporary maximum speed limit", and "Do not switch lanes to overtake queuing traffic" (gov.uk: rules 288 to 307). Our road works guide covers those rules and the pavement-closed question.
Emergency diversion symbols appear on motorway signs as well as on other main roads. Our motorway rules guide covers lane discipline, leaving the motorway and what the overhead signals mean.
Why the colour matters
Yellow is not one of the main direction-sign colours. Blue signs are for motorways, green for primary routes and white for local routes, as our ring road sign guide explains, and brown is for tourist destinations.
The diversion symbols are black on yellow patches, and the Diversion route sign is yellow too, so they stand out from the permanent route colours around them. Our road signs guide sets out how signs are grouped by shape and colour.
How the theory test asks about it
Road signs are one of the theory test's subject areas, and Know your traffic signs is one of the books gov.uk says the questions are based on (gov.uk: revision and practice). Gov.uk does not publish the questions, so we cannot say how often diversion signs appear.
A sign question might show a yellow sign with a black shape and ask what it is for. The answer is that it marks a diversion route: follow it when a temporary sign tells you to. You can practise road sign questions with our free practice questions.
Start free
Start free with the theorytest.ai diagnostic to see whether road signs are a weak area for you. theorytest.ai is independent and is not affiliated with the DVSA or the Department for Transport.
Frequently asked questions
What do the yellow square, triangle, diamond and circle signs mean?
They are emergency diversion route symbols. When a motorway or main road is closed, a temporary sign tells you which symbol to follow round the closure.
What signs do you need for a diversion route?
A temporary sign telling drivers to follow the diversion, then the symbol or route number on the direction signs along the way. For planned closures, temporary yellow diversion signs are used.
What colour are diversion signs?
Yellow with black symbols or black text. The emergency symbols are black on yellow patches, and the "Diversion route" sign is yellow with a black border.
Do the diversion symbols stay up when there is no diversion?
They can. Know your traffic signs says the symbols "may be permanently displayed on existing direction signs, including motorway signs".
Does each shape always mean the same route?
No. Gov.uk gives no fixed meaning to each shape. Follow the symbol the temporary sign names for the closure you are on.