A Traffic Impact Study (TIS) is a technical report that evaluates how a proposed development will affect traffic on the surrounding road network and what improvements are needed to accommodate it. It is triggered when a development generates traffic above a municipal or regional threshold, commonly around 100 new peak-hour trips. It is prepared by a licensed transportation engineer, must use a study scope agreed with the municipality and any regional roads authority, and typically drives road, turn-lane, and access conditions attached to approval.
Underestimate the Traffic Impact Study at your peril. It is the study most likely to attach an expensive physical condition to your approval: a new turn lane, a signal, a road widening, or a restricted access that changes the site plan. Developers who treat it as a box to check discover its conclusions dictate site geometry after the layout is already fixed.
A Traffic Impact Study is a technical report that models how the traffic a development generates will affect nearby intersections, road segments, and access points. It forecasts trip generation, distributes those trips onto the network, and tests whether intersections still operate acceptably, then recommends improvements where they do not.
In two-tier municipalities the study often has to satisfy both the local city and the regional roads authority, each with its own standards. The scope, the study intersections, and the horizon years are agreed with those authorities before the analysis starts, which is why the terms of reference matter as much as the modelling.
A Traffic Impact Study is generally triggered when a development crosses a trip-generation or access threshold set by the municipality or region. Common triggers include:
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Check my site →A Traffic Impact Study is prepared by a transportation or traffic engineer, licensed as a Professional Engineer (P.Eng.) in Ontario, usually within a transportation consulting firm. Where a regional road is involved, the engineer must apply that region’s traffic guidelines, which can be stricter than the local municipality’s.
A complete Traffic Impact Study typically contains:
| Factor | Typical range | What drives it |
|---|---|---|
| Consultant fee | $6,000 to $30,000+ | Number of study intersections, horizon years, and regional-road involvement |
| Preparation time | 4 to 10 weeks | Turning-movement counts must often be collected in a non-holiday period |
| Municipal review | Weeks to months per cycle | Circulation to commenting agencies and revision cycles |
Traffic counts cannot be collected during summer or holiday periods without a seasonal adjustment, so a study started at the wrong time of year can add weeks before analysis even begins. Scope the TIS early.
Thresholds and guidelines vary widely. The Region of Peel, York Region, Halton Region, and Durham Region each publish their own transportation study guidelines that apply on regional roads, and they frequently differ from the local city standard. A site fronting a regional road effectively needs a study that satisfies the stricter of the two. Toronto applies its own Transportation Impact Study guidelines with an active-transportation and transit focus.
A Traffic Impact Study (TIS) is a technical report that evaluates how a proposed development will affect traffic on surrounding roads and intersections, and what improvements are needed to accommodate it. It forecasts trip generation, tests intersection capacity, and recommends road, signal, turn-lane, and access changes. It is prepared by a licensed transportation engineer.
A Traffic Impact Study is generally required when a development generates net new peak-hour trips above the municipal threshold, commonly around 100, when it adds or modifies an access onto a regional or arterial road, or when a rezoning intensifies the use. The regional roads authority can also require one on any site fronting a regional road.
A Traffic Impact Study typically costs between $6,000 and $30,000 or more, driven by the number of study intersections, the horizon years analyzed, and whether a regional roads authority is involved. Collecting turning-movement counts outside summer and holiday periods can add time and cost.
A Traffic Impact Study is prepared by a transportation or traffic engineer licensed as a Professional Engineer (P.Eng.) in Ontario, usually within a transportation consulting firm. On regional roads the engineer must apply the region’s traffic guidelines, which can be stricter than the local municipality’s.
They are the same type of study; municipalities use different names. Toronto and some other cities call it a Transportation Impact Study and place more emphasis on transit and active transportation. The core analysis, trip generation and intersection capacity, is the same. Confirm the exact title and scope at pre-application consultation.
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