The negative environmental impacts of the existing 4 bridges all in the downtown are is huge… and the new bridge in the East is badly needed to reduce carbon emissions from car and truck pollution.  Linking the Ontario and Quebec highway systems with interchanges (not signalized intersections) would reduce idling… and lower impacts on adjacent neighbourhoods.  This bridge has been studied for over 50 years… get it done!  And remember the political mistake when the McDonald-Cartier bridge was NOT linked to the Vanier Parkway… leaving terrible traffic problems on King Edward.  Get it right this time… link the 2 highways (50 and 417) with high quality vehicle moving grade separated roads…