Garden Bridge, the sequel

After the garden bridge debacle cost £43 million of public money (£24 million by TfL) before collapsing in ignominy we would normally assume that politicians as well as TfL would learn from mistakes made.

But quietly another debacle is gathering pace, in October 2016 Mayor Sadiq Khan announced that a new cycling and pedestrian bridge would be built to connect Rotherhithe and Canary Wharf, he said ‘the new bridge could be open by as soon as 2020’. But the TfL team to deliver the project did not start work until early 2017. They knew they had to deliver a bridge and deliver it quickly before they had done any work looking at options.

The new bridge will be the largest pedestrian and cycling bridge in the world. It will also be the largest vertical lifting bridge in the world in order to allow ships through underneath. All to replace the existing pedestrian ferry which has never been full. One of the main justifications for the bridge is to relieve pressure on the Jubilee line between Canada Water and Canary Wharf after TfL decided not to buy ten extra Jubilee line trains because TfL did not think they were needed to relieve capacity.

In October 2016 I wrote to the then Deputy Mayor for London responsible for Transport suggesting that as an interim step that they make the existing ferry free to use. It would allow TfL to understand pedestrian demand from the existing population in Rotherhithe (the ferry has a very limited ability to carry bicycles but that could be expanded). TfL refused. This has been the fundamental problem all along with TfL. The refusal to consider alternatives which would contradict the Mayors publicly stated promise of a bridge. A promise made the same day he announced that the Silvertown road tunnel would go ahead (perhaps to appease the green lobby he felt he had to offer them a clean bridge?). 
 
If you believe funds are unlimited then this bridge might make sense though it cannot be open 247 due to the need to open for ships passing by (up to 60 minutes for large ships). As of February 2019, TfL has already spent £9.9 million on the new bridge and the TfL budget suggests another £8 million to be spent this year before planning permission is even sought. But the cost of this bridge is becoming the critical issue. 
 
TfL originally said it will cost between £120 and £180 million to build and £2.4 million a year to run each year (it will need to be staffed 247 like Tower Bridge). But other reports say it will cost £200 million to build and unofficially TfL do not dispute that the build cost may go to £400 million. We should get the next estimate of costs in late April but £300 million seem to be a fair assumption of the cost for now (the shorter and simpler garden bridge was originally estimated to cost £60 million and ended up being forecast to cost over £200 million).
 
TfL assume the equivalent of 3,333 pedestrians and 1,875 cyclists will use the bridge each day. Although with a 27-minute walk from Canary Wharf to the main area of new development at Canada Water across the 800-meter-long bridge (assuming not closed for ships) it is not clear how many people will make that walk on a dark winter’s night. If it did cost £300 million to build and £2.4 million a year to operate that is a capital cost of £57,604 to build per user and £461 a year to operate per user (the bridge would be free to use). The benefit/cost ratio for the proposed bridge suggest that it maybe negative with a value possibly as low as  0.7 (1 being value for money), the ferry benefit/cost ratio starts at 1.

TfL did model the cost of up to three electric roll on roll off electric ferries and new pontoons at £30 million + £2.4 million a year to run (same as the bridge). But thereafter they have actively discounted it as an option even though we know it would cost less, be more comfortable in winter and would often be quicker to cross for pedestrians.
 
But the main cost is the opportunity cost. £300 million on a bridge is about 21% of the total Healthy Streets capital programme between 2019-2024. If we build a bridge what projects won’t now take place elsewhere? The main justification for the bridge is to encourage more cycling and walking, but perhaps smaller projects will deliver more benefits?
 
TfL will say that the last consultation showed that 93% supported the bridge but only 37% of respondents said they would use the bridge to commute, 56% would use for leisure use. But that consultation never mentioned the ferry as an option, nor the cost of the bridge!
 
A ferry does not mean you cannot later build a bridge later if the ferries are packed each day (you can move the ferries and their pontoons easily to other locations). But the reverse is not true, if you build a bridge which is then under-used it is too late.
 
The Mayor of London should first test demand for this new bridge by making the existing ferry free to use. Then when more user data is available re-consult people offering two choices: an expensive but permanent bridge and a cheaper roll on roll off electric ferry. Failure to do so means that the Transport and Works Order which would give the bridge permission to go ahead would fail as TfL won’t be able to prove that they properly considered alternatives. But it is possible that is the intention. The bridge is now financially unviable, and it would be politically less embarrassing if the Mayor could blame the government for its rejection rather than his own failure in announcing a solution before properly looking at the options (a similar mistake to those made by Boris Johnson).

Picture below of a vertical lifting bridge in France so that you can see how it works