Buried in HHB’s submission to the UARB for a toll increase, is the options study for rehabbing the Mackay Bridge. The Study comes to the conclusion that a new bridge is probably the best way forward, to be in service for 2040.
when it was built, the MacKay was built more lightly then a modern bridge would be. this means it flexes more, and is prone to more wear. it also means rehabbing the bridge is going to me more difficult then doing the MacDonald bridge.
The preferred alignment for the new bridge is the blue line, which leads to a 500m suspended span between the towers. there is more land and space available to the north of the bridge, and alignment 3 (in green) would require demolition of houses in Halifax. the red option is for a 800m cable stay bridge that goes clear across bio.
The new bridge is would feature 2 traffic lanes in each direction, with a third transit priority lane, and Active transportation lanes on both sides of the bridge. The new bridge deck would be 10m (~30′) higher then the current deck for ship clearance and to accommodate 100 year sea level change.
above is the 500m centre span cable stay bridge. It is considered to be the most economical option, and features concrete H towers. it would be similar to the current bridge footprint, just to the north.
below is the 800m centre span bridge. the towers for this bridge are both located on land and the bridge clears BIO by 65m.
below is the tower comparison for the 800m centre span bridge compared to the current towers.
This bridge also looks the best. Please build this one.
the study also covered replacement suspension bridges, and options for rehabilitating and twining the current bridge. You can read the full report here (7mb .pdf)