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Emergency Detour Routes

Ontario's highways carry over eight million drivers and nine million registered vehicles every year. Highway 401 in particular is a major east-west route for various forms of travel including the movement of goods and services. On occasion, incidents occur on these highways resulting in significant congestion and disruption to the driving public.

As a result of transportation issues associated with major highway closures, the Regional Municipality of Durham has partnered with the Ontario Ministry of Transportation to establish an Emergency Detour Routing system for Highway 401. Emergency Detour Routes (EDR) is now in place to help guide motorists along pre-determined routes throughout the Region in the event of an unplanned highway closure.

EDR Signage

Permanent yellow and black signs are clearly visible near the start (refer to Figure 1) of the highway closure, and continue to be displayed to motorists with EDR markers (refer to Figure 2) along the alternate routes.  The detour route signs are positioned to guide drivers in the event that a major accident, hazardous material spill or related incident occurs on Highway 401 that results in a highway closure.

Figure 1 - Emergency Detour Route (EDR)
This sign will be visible near the start of the closure

EDR route sign

Figure 2 - Emergency Detour Route (EDR) Markers
Follow these route markers along the temporary emergency detour to navigate back to the highway.

EDR route sign EDR route sign

Frequently Asked Questions

Why do we need Emergency Detour Routes (EDRs)?

To provide drivers with a pre-determined route when a provincial highway is closed.


When are emergency highway closures necessary?

These unscheduled closures are required when a highway is physically impassable or when emergency work cannot be performed in traffic.


How long will the Emergency Detour Route (EDR) be activated for?

The duration of a highway closure will vary depending on the extent and nature of the incident.


Who decides when the highway should be closed or opened?

The police have the authority to close highways. An officer at the incident will determine when to reopen the highway and deactivate the Emergency Detour Route (EDR).


I have a large truck carrying an oversized or overweight load. Can I use the Emergency Detour Route (EDR)?

No. Oversized or overweight loads travel under permit-defined routes and are not permitted on any other route. The police will direct you to park in a safe location on the highway until it reopens.


I live in an area that the Emergency Detour Route (EDR) goes through. How will I be affected?

While the Emergency Detour Route (EDR) is activated there will be an increase in traffic. This might also include more trucks. Regional and Provincial police staff may be present to direct traffic at key intersections and monitor the use of the Emergency Detour Route (EDR).


How are the Emergency Detour Routes (EDRs) selected?

Emergency Detour Routes (EDRs) are developed by the Region of Durham, in collaboration with the Ministry of Transportation of Ontario. They are based on several factors including travel time and a route's ability to efficiently accommodate increased traffic volumes.

EDR Maps

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Click on any of the documents below to open the map:

EDR 401 - IC_394 to IC_399 – City of Pickering
EDR 401 - IC_401 to IC_404 – Town of Ajax
EDR 401 - IC_410 to IC_412 - Town of Whitby
EDR 401 - IC_416 to IC_419 - City of Oshawa
EDR 401 - IC_425 to IC_428 - Municipality of Clarington
EDR 401 - IC_431 to IC_436 – Municipality of Clarington
EDR 401 - IC_436 to IC_440 – Municipality of Clarington
EDR 401 - IC_440 to IC_448 – Municipality of Clarington