An upgrade of  Main Street and the Main Street Viaduct, one of the largest projects of the Saint John construction season, promises major improvements — and corrects some old mistakes.

When the work is completed in late summer, Main Street speed limits will have dropped to 50 kilometres an hour from 60, and the number of lanes reduced to four from six  — two in each direction.

Accessible infrastructure like audible traffic lights and tactile sidewalks are being added to the street, along with gre…