Traffic Offences
Unnecessary Slow Driving in Ontario
Ontario doesn't post a minimum speed on most roads — but driving unreasonably slowly and obstructing other traffic can still result in a ticket under section 132 of the Highway Traffic Act.
Quick answer: Section 132 of the Highway Traffic Act makes it an offence to drive at a speed "so slow as to obstruct or impede the normal and reasonable movement of traffic," unless the slower speed is required for safety or compliance with the law. There's no province-wide posted minimum speed in Ontario — the question is whether the slow driving was unnecessary and actually obstructed traffic.
Key Takeaways
- Ontario has no general posted minimum speed; this offence is about obstructing traffic, not falling below a number.
- Driving slowly for a genuine safety reason -- weather, road conditions, mechanical issues -- is a recognized defence.
- Reported fines commonly range from roughly $150 to $1,000, with 2 demerit points reported for a conviction.
- Most charges arise where a slow driver blocks a single-lane road and traffic backs up behind them.
What section 132 actually says
Section 132 of the Highway Traffic Act prohibits driving "at such a slow speed as to impede or block the normal and reasonable movement of traffic," except where the slower speed is necessary for safe operation or is required by law. The section is written as the mirror image of speeding offences: instead of penalizing a driver for going too fast, it penalizes driving so slowly, without a legitimate reason, that it obstructs everyone behind them.
Why there's no minimum speed to point to
Unlike speeding, where an officer can point to a posted limit and a radar reading, there's no equivalent posted "minimum" on most Ontario roads. That makes this a more judgment-based offence: it typically comes down to whether the slow speed was objectively unnecessary in the circumstances and whether it actually obstructed other traffic, not just whether the driver was going slower than most vehicles around them.
When slow driving is not an offence
The provision explicitly carves out situations where driving slowly is required for safe operation of the vehicle or compliance with the law -- for example, slowing for poor weather, a rough or icy road surface, a mechanical problem, or another legitimate safety concern. A driver who can point to one of these reasons has a recognized basis to contest a charge, since the offence is specifically about driving slowly without necessity.
Reported penalties
Reported fine ranges for unnecessary slow driving commonly run from around $150 to $1,000, with 2 demerit points reported on conviction. As with other Highway Traffic Act offences, the exact amount set out in the current regulations and printed on your own ticket is the reliable figure for your specific case.
Frequently Asked Questions
Is there a minimum speed limit in Ontario?
No general posted minimum applies on most Ontario roads. Section 132 instead targets slow driving that's unnecessary and that obstructs the normal, reasonable flow of traffic.
Can I be ticketed for driving slowly in bad weather?
The law specifically exempts slow driving that's necessary for safe operation, which generally includes slowing down for poor weather or road conditions.
Does this apply to highway "left lane" slow driving?
It can, where slow driving in a passing lane unreasonably obstructs traffic behind, though these situations are also sometimes addressed through other provisions dealing with lane use.
Sources
Charged With Unnecessary Slow Driving?
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