The work to cover the Ville Marie Expressway means one road spanning the highway is now closed and will remain closed for the next year and a half.
Hotel de Ville between Viger and Saint Antoine closed on Thursday and will only reopen in November 2017.
It's all part of the two-year, $140 million plan to cover part of the highway and build a park next to the CHUM superhospital for Montreal's 375th anniversary.
This weekend that section of the Ville Marie Expressway will be subject to multiple closures as Transport Quebec crews prepare the highway to be covered.