Transport Canada uses the Travel Time Index (TTI) to measure urban mobility. This key indicator tracks the performance of urban trade corridors, helping to understand the impact of congestion on the economy.
Urban mobility refers to a person’s ability to move around the city where they live and work. Congestion on city roads reduces mobility, which is not only an individual inconvenience but also has an economic impact. While the amount of additional time spent in traffic, excess fuel consumed, and other costs of congestion may be large in Canada, the full impact is not known. Using key indicators to evaluate congestion, its cost, and its impact on the economy is the first step to understanding the magnitude of the problem.
To that end, Transport Canada is now using a key mobility indicator - the travel time index or TTI - to track the performance of a series of key urban trade corridors across Canada. Put simply, the TTI is the ratio of actual travel time to the ideal or “free-flow” travel time or, equivalently, the ratio of free-flow speed to actual speed. The travel time index is recommended by the Transportation Association of Canada (TAC) and used by the United States Federal Highway Administration (FHWA).
See more about the Travel Time Index (TTI)