Detour

Reference Table

Core Sign Facts

Structured metadata for quick AI parsing and theory-test recall.

Core facts about Detour
Sign name	Detour
Sign type	Roadwork Signs
Expected in DTT?	Yes. This sign is commonly covered in Irish driving theory test preparation.
Action required	This sign indicates the beginning of a mandatory official diversion route due to road closure or major roadworks ahead. Your intended route is completely blocked and you must follow the designated detour path. The sign marks where you should begin following yellow-and-black temporary direction signs rather than normal road signage. This is not a suggestion but a legal requirement - the alternative route ahead is either physically impossible or legally prohibited. All traffic must use the official detour, which has been planned to handle the expected volume safely while minimizing disruption to local communities along the diversion route.
Appearance	Triangular / Amber and black
Typical location	Detour signs are strategically placed throughout Ireland's road network when major roadworks, bridge repairs, or emergency closures require complete route diversions. They're commonly seen on approaches to Dublin city centre when sections of the M50 or major arteries like the N7 or N4 need temporary closure. You'll encounter these signs frequently on regional routes in counties like Kerry, Donegal, and Mayo where bridge maintenance on narrow roads necessitates longer diversions. They're also prominent during festival periods in towns like Kilkenny or Westport when city centres are temporarily closed to through traffic, requiring extensive detour routes via ring roads.

This page explains what the Detour sign means, where it is typically found, and how drivers should respond in Ireland. It also connects you to closely related signs so you can compare similar road situations and build stronger theory-test recall.

What Does This Sign Mean?

Official diversion around closure or works.

Key Points:

↪️ Indicates the start of a mandatory diversion due to roadworks or a closure.

🗺️ Follow the signed detour route to get around the obstruction.

🛑 Your original route is not accessible.

More Roadwork Signs Signs

Convoy System in Operation

Traffic guided through works by lead vehicle convoy.

Cyclists Keep Left

Cyclists directed to keep left in works zone.

Cyclists Keep Right

Cyclists directed to keep right in special layout.

Detour Destination

Indicates end destination of signed detour route.

Diverted Traffic (Left)

Detoured traffic directed left.

Diverted Traffic (Right)

Detoured traffic directed right.

Complete Guide to This Sign

Where You'll Find This Sign

Detour signs are strategically placed throughout Ireland's road network when major roadworks, bridge repairs, or emergency closures require complete route diversions.

They're commonly seen on approaches to Dublin city centre when sections of the M50 or major arteries like the N7 or N4 need temporary closure.

You'll encounter these signs frequently on regional routes in counties like Kerry, Donegal, and Mayo where bridge maintenance on narrow roads necessitates longer diversions.

They're also prominent during festival periods in towns like Kilkenny or Westport when city centres are temporarily closed to through traffic, requiring extensive detour routes via ring roads.

What This Means for Drivers

This sign indicates the beginning of a mandatory official diversion route due to road closure or major roadworks ahead.

Your intended route is completely blocked and you must follow the designated detour path.

The sign marks where you should begin following yellow-and-black temporary direction signs rather than normal road signage.

This is not a suggestion but a legal requirement - the alternative route ahead is either physically impossible or legally prohibited.

All traffic must use the official detour, which has been planned to handle the expected volume safely while minimizing disruption to local communities along the diversion route.

Penalties & Legal Consequences

Following detour signs is mandatory under the Road Traffic Act.

Attempting to proceed past a detour sign into a closed road section can result in charges for dangerous driving, with penalties including fines up to €5,000, potential imprisonment up to 6 months, and mandatory driving disqualification.

Police regularly monitor closed routes and issue on-the-spot fines of €80-€120 for unauthorized access.

If your actions endanger construction workers or cause accidents, penalties increase significantly with possible criminal charges.

Additionally, insurance claims may be invalidated if accidents occur while deliberately ignoring mandatory detour signs.

Emergency vehicles may also issue fixed penalty notices of €60 for non-compliance with traffic management orders.

Appears in Driving Test?

Detour signs and temporary traffic management form a significant part of the Irish driving theory test curriculum.

You need to understand that detour signs indicate mandatory diversions, not optional alternative routes.

Test questions may cover scenarios where you must choose between following a detour or attempting to continue on your original route.

The correct answer is always to follow the official detour.

During practical tests, encountering detour signs allows examiners to assess your compliance with temporary traffic management, your ability to follow sequential directional signs, and your awareness that normal route planning must be adapted.

Proper response to detours demonstrates respect for road safety regulations and construction worker protection.

Frequently Asked Questions about the Detour Sign

What does the Detour sign mean in Ireland?

In Ireland, the Detour sign indicates: Official diversion around closure or works. Understanding this is crucial for safe driving and passing your DTT.

What type of sign is the Detour?

The "Detour" is officially classified as part of the ROADWORK group in Ireland. Like other signs of this type, it alerts drivers to specific rules, hazards, or information they must immediately observe.

Will the Detour sign appear on the Irish Theory Test?

Yes, you should expect the Detour sign to appear on your Irish Driving Theory Test (DTT). You must be able to identify it as a ROADWORK and know what it requires from you as a driver.

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Detour

Reference Table

Core Sign Facts

Structured metadata for quick AI parsing and theory-test recall.

Core facts about Detour
Sign name	Detour
Sign type	Roadwork Signs
Expected in DTT?	Yes. This sign is commonly covered in Irish driving theory test preparation.
Action required	This sign indicates the beginning of a mandatory official diversion route due to road closure or major roadworks ahead. Your intended route is completely blocked and you must follow the designated detour path. The sign marks where you should begin following yellow-and-black temporary direction signs rather than normal road signage. This is not a suggestion but a legal requirement - the alternative route ahead is either physically impossible or legally prohibited. All traffic must use the official detour, which has been planned to handle the expected volume safely while minimizing disruption to local communities along the diversion route.
Appearance	Triangular / Amber and black
Typical location	Detour signs are strategically placed throughout Ireland's road network when major roadworks, bridge repairs, or emergency closures require complete route diversions. They're commonly seen on approaches to Dublin city centre when sections of the M50 or major arteries like the N7 or N4 need temporary closure. You'll encounter these signs frequently on regional routes in counties like Kerry, Donegal, and Mayo where bridge maintenance on narrow roads necessitates longer diversions. They're also prominent during festival periods in towns like Kilkenny or Westport when city centres are temporarily closed to through traffic, requiring extensive detour routes via ring roads.