In my earlier post, “Mind the Gap: When Sidewalk Transitions Become Legal Traps,” I walked through Ontario’s now-familiar benchmark, namely that on municipal sidewalks, a vertical discontinuity under 2 cm is generally not a legal defect. That conclusion flows from Ontario’s Minimum Maintenance Standards for Municipal Highways (MMS), O. Reg. 239/02, which deems a sidewalk “in a state of repair” at ≤ 2 cm. If it’s > 2 cm, the municipality must treat it within 14 days after acquiring actual knowledge.^[1]

In Cromarty v. Waterloo (City)^[2]
, Justice Broad applied that framework and found no liability where the measured deflection was below 2 cm—consistent with the MMS and with a reasonableness standard under s. 44 of the Municipal Act, 2001.

That was the easy part.

This sequel tackles the harder question: When does a ledge just above 2 cm become a real trip hazard—and when does it stop being a “defect” at all?

Start with the only bright line Ontario actually gives you for municipal sidewalks: the Minimum Maintenance Standards fix 2 cm as the dividing line. A discontinuity at or below 2 cm is deemed to be in a state of repair; once it exceeds 2 cm, the municipality’s maintenance obligation is triggered, typically within fourteen days after it has actual knowledge. Courts treat compliance with that standard as a powerful shield for municipalities.

Above 2 cm, there isn’t a new magic number. Ontario decisions don’t swap in a higher threshold. They assess the facts—where the discontinuity sits, how it was measured, what the inspection and notice history shows, the conditions at the time, and how the pedestrian approached the area.

A useful marker is Grayling v. Haldimand (County)^[3], where the trial court found that a change in level between three-quarters of an inch and one-and-a-quarter inches (about 1.9–3.2 cm) constituted a trip hazard and resulted in liability, tempered by a 50% reduction for contributory negligence. Although Grayling isn’t an MMS case and turns on its facts, it illustrates a practical truth: once you’re in the two-to-three-centimetre zone, liability becomes genuinely contestable.

There is no Ontario statute or regulation that declares an “upper height” at which responsibility automatically shifts to the pedestrian. Instead, the analysis turns on the character and location of the elevation change. Purpose-built changes in level—curbs, steps, thresholds—are not disrepair merely because they exceed 2 cm; the question is whether they are reasonably safe given their function and context, including lighting, contrast, sightlines, handrails, and maintenance.

The standard is reasonableness, not perfection. For municipalities that standard is anchored in section 44 of the Municipal Act, 2001 and reinforced by MMS compliance.  For private occupiers it’s section 3(1) of the Occupiers’ Liability Act^[4].
, which imposes a duty to take reasonable care to see that persons are reasonably safe. The OLA sets no fixed height. In practical terms, a 10–15 cm curb is an intended feature a reasonable user is expected to notice and negotiate, whereas a 2.5–3 cm slab heave right in the pedestrian desire line can be actionable because it is unintended, unexpected, and—if known and left unremedied—unreasonable^[5].

Pulling the strands together, three working rules emerge.

First, on municipal sidewalks, ≤ 2 cm is deemed in repair by regulation and claims usually fail if the municipality can prove MMS compliance (as cases like Cromarty v. Waterloo (City) underscore).

Second, an unintended discontinuity above 2 cm is presumptively unsafe unless the municipality can show timely action within the MMS timelines after notice; those cases turn on meticulous measurement, inspection records, and the notice trail.

Third, in the 1.9–3.2 cm range recognized in Grayling, courts have treated the condition as a realistic hazard while still weighing the pedestrian’s responsibility to watch where they’re going. Contributory negligence can be significant. Purpose-built changes in elevation sit in a different box. They are typically not defects at all, and the inquiry shifts to visibility and maintenance rather than raw height. There is no fixed “safe height” that ends that analysis.

Evidence wins—or loses—these files. Cromarty is a reminder that the tool, method, and location of measurement can decide a close case. Photograph the discontinuity, use a square, and record multiple readings. Knowledge and timelines often carry the day for municipalities in > 2 cm cases. No actual knowledge before the incident, or prompt remediation within fourteen days after knowledge, is frequently decisive. Character and location matter as well: an obvious curb is judged differently than an unexpected heave at the lip of a crosswalk, and Grayling shows that even when a hazard exists, fault may be shared.

The bottom line is blunt. Ontario law does not set a statutory upper height at which every ledge becomes the pedestrian’s problem. What the law does provide is regulatory certainty at 2 cm for municipal sidewalks. Above that, unintended discontinuities become legally risky unless they are addressed promptly after notice. Beyond that, the law distinguishes defects from designed level changes. A high curb is expected and usually not a defect. An unseen 2.5–3 cm slab rise in a pedestrian pathway can be, and has been, treated as a trip hazard, with contributory negligence allocated where appropriate.

If you’re litigating one of these, measure carefully, nail down notice and inspection evidence, and frame the condition properly at the outset. Is it disrepair or design? That fork often decides the case.