You wouldn’t know it, but it’s the start of car-free week; people will see a tent on Phillips Square where various events are scheduled to “encourage” people to commute without their cars. (Why not make transit free this week?)
On Thursday a small bit of Ste-Catherine will be closed and Arcade Fire performs in the evening. Some boroughs will close parts of other streets on different days – the list is at the foot of the AMT page. Underwhelming, at least as an environmental effort – I don’t doubt the concert will be memorable. The Quartier des Spectacles page gives a mass of details on which streets will be closed, which buses rerouted and so forth for the event.