From Squeaky Wheels, Montreal Gazette, July 5, 2015

Q: Throughout Montreal and other municipalities rush hour is generally 7-9 a.m. and 4-6 p.m. During these four hours, traffic is forced to avoid left turns because of the higher volumes. This is understandable. Why does the city of Côte-St-Luc designate rush hour 7-10 a.m. and 3-7 p.m., a total of 7 hours compared with 4 hours? This is on Fleet, which is the only route in and out of Côte-St-Luc

Isaac Alt, Côte-St-Luc

A: Côte-St-Luc spokesperson Darryl Levine said the extended rush periods are a relatively new occurrence. Before that, Côte Saint-Luc didn’t allow left turns on Fleet Rd. from 7 a.m. to 9 p.m. This was to avoid traffic delays on Fleet Rd. during rush hour and to stop motorists from using the side streets as shortcuts during the rest of the day, Levine said.
However, by 2010 the city concluded this extended left-turn restriction was having unintended consequences, because vehicles were finding other ways around and this created traffic on smaller side streets. In 2010, after a consultation with residents, the city decided to introduce the current rush-period restrictions. This was seen as striking a good balance between people who wanted to turn off of Fleet, and the residents on those streets that didn’t want through traffic in front of their homes.
“Having an extended rush hour time period means two hours of less traffic on the side streets in the immediate area,” Levine said. “So those streets now get more vehicles than in 2010, but less than if the would have if the rush hour left turn restriction had been made shorter.”