although it was completed from manitoba to quebec in 1960, many upgrades to the original routing of highway 17 had and would take place over the years. in addition to bypasses around almost every urban centre it encountered, many original sections have been downloaded to regional and local jurisdiction or decommissioned entirely to lay abandoned in the forest. of special note is reroutings in the ottawa valley – where the highway follows very little of the original routing – and around thunder bay, where it has undergone several reroutings and upgrades since the 1920s. in the following section, upgrades are listed from west to east due to complex chronologies.