City traffic experts find no evidence daylight saving time leads to traffic carnage

Coun. Matt Allard's belief that daylight saving time spurs more traffic accidents has been crushed under the weight of city collision data.

In the fall, the St. Boniface councillor asked city traffic analysts to review collision data to see whether the biannual time change affects traffic accidents. At the time, he said he wanted to see "whether there is a safety risk to the public stemming from fatigued drivers the morning after daylight savings time."

• St. Boniface councillor concerned about daylight saving time

In a report to city council's public works committee, Winnipeg traffic analyst Michelle Chester, traffic management engineer Stephen Chapman and transportation planning engineer David Tang state there is no correlation between daylight time and traffic accidents or a threat to public safety.

Looking at four years of collision data, they noted more accidents occur during the winter, when the streets are more likely to be covered in ice and snow, than during the summer, when streets are in better condition.

"The monthly collision data indicates that the number of collisions from month-to-month reflects a seasonal effect; with an increase in the number of collisions observed during the fall and winter months when the weather worsens and a decrease in the number of collisions observed during the spring and summer months when the weather improves," they write.

Daylight-saving fatigue is not a factor, they said, as the increase in winter accidents takes place after clocks are set back an hour, adding an hour of sleep — and the summer decrease in collisions takes place after clocks are set ahead one hour, depriving motorists of sleep. 

Along with asking for a report about daylight saving time, Allard also requested reports about the impact of driverless cars, zipper merges and getting motorists to open their doors using their right hands.