Transport Canada has lifted an order reducing the speed limit to 16 kilometres an hour for trains running along a six-kilometre stretch of track in the municipality of Sorel-Tracy.
It has been restored to 65 kilometres an hour for all but one kilometre of that stretch, where the limit will be reduced to 24 kilometres an hour.
The transport department's order came following an inspection of the tracks. Millions of litres of crude oil are shipped along the tracks daily.
CN is now conducting repairs to the tracks.