How to Fix the Northern Line

I have a friend John (not his real name) who has a bike (or had, until it got nicked a few months back). He's talked in the past about cycling to work but never quite got round to it.

John lives in Tooting. A couple of weeks back, he was walking back from the tube station, and happened upon the aftermath of a cycle collision, on CSH#7. An ambulance was in attendance. "The guy wasn't moving", he told me. "It didn't look good".

John is exactly the kind of person TfL are desperately trying to encourage to get on a bike to relieve congestion on the Northern Line. The BBC reported "Travellers are being asked to avoid getting on the Northern Line between Tooting Bec and Clapham North between 0800 GMT and 0845."  They are advised to walk or cycle instead.

Unfortunately for TfL, their advice to cycle might be heeded more if they hadn't made such a mess of implementing CSH#7 - which closely follows the Northern Line for much of its route. CSH#7 is exactly the wrong way to encourage anyone to cycle: almost everyone I know who uses CSH#7 has witnessed a collision on it.

CSH#7 follows the same basic design principles as the first phase of CSH#2, recently described "as an accident waiting to happen". Those principles can be summed up as follows. "Paint a blue stripe, and don't worry too much about major or minor junction safety, and don't do anything that might impact car parking or traffic flow. (Motor traffic,of course, is there any other kind?)"

The cheapest way to increase Northern Line capacity is to get people off it and onto other transport modes. Unfortunately, the most obvious alternative - buses - are already creaking at the seams. Val Shawcross wrote in the Guardian:

"Over the past 10 years, London's population grew by 80,000 a year and the number of bus kilometres by 109m. But over the coming decade, the population is forecast to grow by 100,000 a year while bus kilometres covered will increase by just 20m. This means more overcrowding on buses, and more people left behind at bus stops. London's buses are already frequently overcrowded. A quarter of those responding to our passenger survey said their bus was overcrowded and yet TfL has no plans to significantly increase services."

The underlying problems are twofold:
1. Failure to manage road congestion. Congestion slows down buses, making them an unattractive, slow, unreliable option, and forcing people to take the tube.
2. Failure to prioritize cycle safety. Failure to prioritize cycle safety ensures that most people don't consider cycling as a transport option.

What this all boils down to is that on the roads, TfL treats every road journey with equal priority: the least necessary journeys and the least efficient transport modes in terms of passengers per square metre of roadspace (private cars and taxis) have the same priority as the most important journeys and the most efficient modes. In the congestion charge zone the incentives are a little more logical but the fact that taxis and private hire vehicles are exempt from the congestion charge means that those vehicles are prevalent, and congestion is still widespread.

TfL also treats every road user as if they had equal safety requirements. TfL behave as if there were no such thing as a vulnerable road user, and as a result would-be cyclists are scared off the roads. (And it's not cycle campaigners or bloggers scaring people off cycling: surveys have been listing fear of traffic as the #1 reason people don't cycle for many years.)

So if people felt safe cycling, how many bikes could you accommodate on roads if you actually tried? Studies show the saturation flow for a single 1-m (3.3 ft) to 1.2-m (4-ft) bicycle lane appears to be between 1,500 and 5,000 bicycles/hr with a majority of the observations falling between 2,000 and 3,500 bicycles/hr. So for two-way flows based on a 10-hr day at maximum capacity, that works out at about 18M journeys per year. The London Underground Major Regeneration Scheme aims to add capacity of 500M extra journeys per year, at a cost of £39bn (2008). The pro-rata cost of 18M journeys per year (our nominal numbers for a 2-way cycle lane) works out at about £1.5bn. The segregated CSH#2 extension cost £2M/mile, and the refurbished, segregated CSH#2 about £20M. CSH#2 currently only carries about 400 cyclists/hour at peak times, which works out at maybe 1M journeys/year, but that's because it's currently unsegregated and therefore reflects the London-wide 2% cycling modal share. Continental infrastructure should bring Continental levels of riders: 2% modal share could turn into 20%, so you can see how levels of 10M journeys/year are not out of reach on CSH#2.  And at costs per journey getting on for 2 orders of magnitude lower than the tube upgrade. As a side benefit, more people would use London's under-used cycle hire scheme, bringing more revenue to TfL.

Now, you'll notice that the above numbers are very rough indeed, but even if you water the assumptions down to very conservative levels, they still indicate that cycling capital investment is incredibly cheap compared with upgrading train capacity. They also indicate the opportunity cost associated with the lack of investment in cycling in London. The Mayor is proposing to spend £913M over the next 10 years on cycling, averaging £91M/year. That is nowhere near enough to built a significant amount of infrastructure to the standard required to actually attract significant numbers of users, and as a result, London will have to spend far more accommodating those users on other forms of transport. Additionally, health experts recently told a parliamentary enquiry that "the NHS spent about £5 billion a year on obesity-related conditions...health services could make £4 of savings for every £1 invested in cycling".

Instead of forecast numbers, lets instead consider some real ones. Since 2006 Seville has increased the number of daily cycling journeys from 5000 to 72,000, bringing modal share from  0.5% to around 7%. The cycle network cost €32m. Compare that with the city's underground system which cost €600 million and carries 40,000 people daily. It's interesting that Seville appears to have spent so little ( €400K/mile) building 80 miles of decent-quality infrastructure in so little time (the first 50 miles built in less than a year), compared with the CSH cost of £2M-£4M per mile, for what can charitably be described as dangerous crap.

If ever there was a cast-iron business case, it is to invest in cycling. Unlike the shaky, wildly-optimistic and naive economic cases that are used to justify road and rail investments. On the plus side, Boris seems now to understand that segregated, decent-quality, Continental-style infrastructure (as opposed to blue paint) is needed to get cycling modal share out of the doldrums, and is finally proposing and planning such routes. Unfortunately, London government (and here the blame falls partly on local government and City Hall, but mainly on central government) have not collectively realized that the massive benefits to be had from cycling - including health-related savings, air pollution reduction, displacement from far more expensive transport alternatives, a more liveable city - cannot be done on a shoestring. Until they realize this, we'll instead be spending far more on massive taxpayer subsidy of public transport that also has some of the highest fares in the world.