https://montecristomagazine.com/community/forgotten-bridges-vancouver
The LGB just wasn't designed with any future capacity in mind.
History of the Lions Gate Bridge https://www.youtube.com/watch?v=JHqi7Kijedw
https://en.wikipedia.org/wiki/Lions_Gate_Bridge#History
https://upload.wikimedia.org/wikipedia/commons/7/7e/Lions_Gate.jpg The inadequate 3 lane LGB is currently the most narrow road bridge in backwards & stubborn Vancouver. It's been in that category since the removal of the 2 lane Fraser Street Bridge in the 1970s. There was a refusal to twin the absurdly narrow LGB between the 1950s & 1970s. By the 1980s there should have been a subway tunnel and an 8 lane tunnel. Then two of the lanes could have been for buses. Georgia Street is 7 lanes wide as it gets closer to Stanley Park. Thus, the main part of a tunnel through the park could have provided 3 general lanes each way & a bus lane each way. Instead, the 7 lanes of the westernmost part of Georgia Street are funneled into a 3 lane causeway & a 3 lane bridge. The LGB would be fantastic as just a bike & foot crossing, with train, bus & road tunnels well beneath & beside it.
The Burrard_Bridge, BB or BSB opened with 6 lanes, but now it only has 4 lanes. There are 2 bike lanes & 2 sidewalks. Had a parallel bike-bridge been built, the BB could have still had 6 lanes. While the BB has a lower level provision for streetcars or tram-trains, Vancouver did its damndest to phase out streetcars well before the 1960s.
The Ironworkers_Memorial_Bridge has 6 lanes, but should also have had 2 wide shoulders & 2 very wide sidewalks. Unfortunatly, there was no provision for a lower deck, as is also the case with all of the other Vancouver bridges. https://en.wikipedia.org/wiki/Ironworkers_Memorial_Second_Narrows_Crossing
Any replacement of the inadequate Ironworkers+Memorial+Bridge should be on the scale of what Perth, Seattle and Montreal have done.
https://en.wikipedia.org/wiki/Granville_Street_Bridge#Third_bridge_(1954)
https://www.youtube.com/watch?app=desktop&v=vPSdF0jRTC4 The Granville-Bridge or GSB is the widest bridge in the city limits. It opened with 8 lanes, but is being transformed into a 6 lane bridge with 2 bike lanes & 2 sidewalks. Had there been a paralel bike & foot bride, the GSB could have still been 8 lanes wide. Then there could have been 2 exclusive bus lanes.
https://vancouver.ca/streets-transportation/granville-bridge-connector.aspx
The Oak Street Bridge should have been 8 lanes wide, with 2 wide sidewalks.
The Knight+Street+Bridge should have been 8 lanes with 2 wide sidewalks. Instead, its a 4 lane chokepoint.
The Arthur+Laing+Bridge should have been at least 6 lanes with 2 proper bike lanes & 2 sidewalks.
If the Cambie_Street_Bridge had 2 very wide sidewalks, then its likely that it would still have 6 lanes instead of 5. https://en.wikipedia.org/wiki/Cambie_Bridge#The_present_bridge
Unfortunatly, bottleneck or chokepoint planning is part of the Vancouver & BC mentality.
Of course BC & the Metro+Vancouver Region just hasn't put enough funds towards proper big-city planning & infrastructure development.