However, just saying 'no' and not proposing anything else isn't constructive.
Er, how so? Because as far as that particular stretch is concerned, I hope they do nothing and leave it well alone. Increasing numbers of people - using nothing more expensive than their own initiative - are cycling/walking into town, many of 'em along that route. The existing BRT plans give such commuters minimal consideration - indeed, the proposed Prince Street Bridge bus routing is utterly daft from a safety POV. I suspect the promised Gov funding partly explains the Council's desire to build, build, build. The passenger/journey time projections (themselves apparently flawed) will do little to ease Bristol's terminal gridlock - be the journey local or from out-of-town.
Better integration with the town planning would also be required for a more sustainable future plan, but that is too big a step for now.
If we are going to really grip the problem, then this should be the first step. The council funding would be better spent on sorting out the mess that is existing Brizzle bus provision. I've recently spent 5 years in Southampton - their Unilink service (a collaboration between the Council, University and Bus co) pishes all over First's efforts.
Where would you put it then?
To be quite frank, I'd use existing road infrastructure. If we are serious about getting people out of cars, we need to be radical about it.