New data suggest the afternoon drive home may be riskier than the drive to work in the morning.
The report says car crashes that result in people being hospitalized are more common in the afternoon and evening than at other times in the day.
The figures were released by the Canadian Institute for Health Information.
They show that in 2010-2011, nearly 4,000 drivers were admitted to hospital between 4 p.m. and midnight after collisions on public roads.
From 8 a.m. to 4 p.m., the figure was just under 2,600 people and from midnight to 8 a.m., 1,800 drivers were in crashes that led to hospitalizations.
"During the day, the morning drive seems to be a lower risk period than the afternoon drive. And it may be that people are doing more driving at the end of the day — running around doing chores,etc.," says Greg Webster, who is CIHI's director of primary health-care and clinical registries.
Though the overall number of hospitalizations for the overnight period was lower than the daytime or late afternoon-evening periods, it is likely there would have been fewer people on the road from midnight to 8 a.m., Webster acknowledges. So the risk of having a collision during the overnight period might actually be higher than during the daytime.
The report doesn't calculate rates — comparing people driving during those periods with those who ended up in hospital after a collision. So the numbers only reflect the volume of such crashes.
And they would only be a portion of all collisions involving injuries. These figures only include people who were hurt badly enough to be admitted to hospital. Anyone who was seen in the emergency room but released, or who died at the scene or en route to a hospital would not be reflected in the figures in this report.
Those uncaptured numbers would be significant. About 2,000 people a year die as a result of motor vehicle collisions every year, CIHI says, and only about one-quarter of them die in hospital.
During the period studied, there were more than 16,200 people admitted to hospital as a result of collisions on public roads. Half of them were drivers, and 19 per cent were passengers. Pedestrians and cyclists made up another 19 per cent and the identities of the remainder were not recorded.
During the period studied, Toronto and Vancouver had the lowest rates of traffic injuries per 100,000 people when the data were broken down by city. The highest rates were in Regina and St. John's, N.L. Breakdowns for Quebec cities were not available.
Webster speculates that the rates may be lower in cities with extensive public transit systems.