Minimum Speed Sign
The minimum speed sign shows the slowest speed drivers are legally permitted to travel on that section of road. Driving slower than the posted minimum without a valid reason is an offence under the Ontario Highway Traffic Act.
Last updated: April 4, 2026
A minimum speed sign is the reverse of a maximum speed sign. It sets a legal floor on how slowly you may travel. These signs exist to prevent very slow vehicles from creating hazards or obstructing the flow of traffic on high-speed roads. If conditions require you to slow below the minimum, such as a mechanical problem or extreme weather, you must use your hazard lights and pull over as soon as safely possible.
Quick Facts
Type
Regulatory Sign
Shape
Rectangular
Colours
White background with black text; speed shown in a circle
In this guide
What does the Minimum Speed Sign mean?
A minimum speed sign is the reverse of a maximum speed sign. It sets a legal floor on how slowly you may travel. These signs exist to prevent very slow vehicles from creating hazards or obstructing the flow of traffic on high-speed roads. If conditions require you to slow below the minimum, such as a mechanical problem or extreme weather, you must use your hazard lights and pull over as soon as safely possible.
What to do when you see it
Maintain at least the minimum posted speed unless a genuine safety hazard requires you to slow down. If you must travel below the minimum for any reason, activate your four-way flashers and move to the shoulder at the first opportunity. Do not drive at the minimum speed in the passing lane if faster traffic is behind you.
Where you'll see it in Ontario
Minimum speed signs are most common on expressways and multi-lane highways such as the 400-series in Ontario. They are rare on local roads. You may also see them on bridges or tunnels where very slow vehicle speeds create wind-related or structural hazards.
G1 test relevance
The G1 test sometimes includes a question identifying the minimum speed sign, which is visually distinct because the speed number appears inside a circle rather than as plain text. Candidates are expected to know that driving below the minimum is an offence and that the sign is rectangular with a circled number.
Common mistakes drivers make
Drivers often confuse the minimum speed sign with an advisory speed sign. The minimum speed is a legal requirement. Driving persistently below the minimum is an offence. Another mistake is stopping on an expressway shoulder for non-emergency reasons, which is also illegal in Ontario.
Related Signs
Speed Limit Sign
The speed limit sign is a white rectangular sign showing the maximum legal speed in kilometres per hour for that section of road. Drivers must not exceed the posted number under normal conditions.
Learn moreHighway Route Sign
Highway route signs identify numbered provincial and county highways in Ontario. Blue shields mark the 400-series expressways, blue rectangles mark provincial roads, and blue markers indicate county roads.
Learn moreMerge Sign
The merge sign warns that two lanes of traffic will combine into one ahead. Drivers must adjust their speed and position to merge smoothly and safely.
Learn moreLane Use Control Sign
Lane use control signs use arrows to show which manoeuvres are permitted from each lane at an intersection. Drivers must follow the arrow in the lane they occupy.
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