Keith Vodden Dr. Douglas Smith - Transports Canada

Ontario Model
The same adjustment techniques are used to move from raw data to adjusted data
based on observations of under-and misreporting. In most cases, calculations in the
Ontario model to estimate non-human consequences are applied to the sub-models
without change. Some adjustments are made to reflect the unique characteristics of
particular models such as more costly tow truck services for large truck collisions and
more delay and pollution for collisions on freeways.
3. Canadian jurisdictions model
Raw data on collisions for each of the thirteen Canadian jurisdictions were
obtained from Traffic Accident Information Database (TRAID). These data have slightly
different formats and coverage by jurisdiction. A first task was to adjust data for each
jurisdiction to the format of the Ontario data. When the detail available in the Ontario
data was missing (for example an injury severity classification or the distribution of
vehicle damage by damage severity) the distribution from Ontario was used to fill in for
the missing values. This resulted in data for all jurisdictions being placed in the format of
the Ontario data.
As a result, the raw data for a jurisdiction (C1—Raw data) were revised (in
C1.1—Revised raw data) to reflect the structure of the data requirements of the Ontario
model. Adjustments were made to handle cases of under and misreporting (in C2—
Adjusted data) based on the observations made in the more detailed analysis for Ontario.
Next the social costs of collisions were estimated based on the characteristics of the
collisions in each jurisdiction using parameters established in the Ontario model (in C3—
Social costs).
Adjusted collision data from the 13 jurisdictions are aggregated to provide results
for Canada as a whole. Social costs for each jurisdiction are also aggregated to produce
social costs for all collisions in Canada.
TNS Canadian Facts, Social and Policy Research 11