Keith Vodden Dr. Douglas Smith - Transports Canada

Appendix A—Detail on Calculations of the Ontario Model
It seems clear that different types of drivers will place different values on time
spent in congested traffic. However, it appears highly unlikely that data would be
available to support a more detailed analysis of how willingness to pay to avoid delays
might vary across different types of drivers. As a result, our approach draws on the
mainstream literature. In this literature, the lower bound would be a value of 50% of the
2004 market wage ($9). The upper bound from Transport Canada’s Urban Congestion in
Canada (2006-Table 1) gives a value of $32.25 per hour for Ontario in 2004. In our
calculations below, we use $20.60 per hour, the average of these two values as an average
value for all road users.
c) Additional fuel use
Incremental fuel costs result from delays (slower speeds), stopping (frequent with
lane closures) and detour distances. The COMPASS data provide the duration of lane
and road closures and the traffic volumes at the time of the incident. From this, we have
estimated idle times and detour/slower driving. The current congestion cost model uses a
stop time of two hours (or the duration of closure whichever is smaller) and a slow
driving/detour time of one hour (or the duration of closure whichever is smaller).
From the U.S. Department of Transportation, we used an estimate of 2.25 litres of
gasoline for each hour spent idling. For detours and delays, we used an average fuel
efficiency amount of 11.25 litres per 100 km. Based on this fuel efficiency, each hour of
detour and delay, in addition to time stopped, consumes 5.5 litres of fuel. Fuel costs of
76.6 cents per litre (from Ontario Ministry of Energy historical price data) are used in the
model for 2004.
d) Additional Pollution
A further social cost of traffic delays caused by collisions is the pollution
associated with extra burning of fossil fuels during the delay. It is widely recognized that
traffic congestion generally, and specifically from collision, contributes to increased
levels of exposure to vehicle emission-related pollutants. Vehicle drivers and passengers
will feel the negative impacts during traffic delays. The non-driving public may also
experience a degradation in the air quality in the area of the collision. Generally, the
costs will be larger in urban areas where roadways are contiguous to large numbers of
residences and persons. There is evidence in the literature that for passengers, pollution
levels inside stopped and idling vehicles, in a group of stopped vehicles, may be from two
to eight times higher than when moving at the speed limit. Any policy-related measures
to reduce collision-related congestion will reduce the health risks to vehicle occupants
and will also reduce general population risk in urban areas. The extensive literature on
air pollution shows that the benefits of risk reduction related to reduced air quality are
substantial. These benefits relate primarily to emissions of air pollutants such as
hydrocarbons (HC), CO, NO x , as well as emissions of greenhouse gases (GHGs). In this
project, we have estimated incremental emissions related to motor vehicle collisions in
TNS Canadian Facts, Social and Policy Research 151