Tuesday, 7 August 2012

London's congestion charge is a success, but has not solved congestion

I’ve spent a couple of months considering the article on Streetsblog which has a stark visual representation of car, bus and cycle traffic in London in the past decade. The hypothesis arising from this is that a lot of the change was due to the congestion charge suppressing car traffic, whilst encouraging use of other modes.

The article alludes to it being a bit more complex than that, but I don't believe that its overall message has the right emphasis.  It would be quite wrong to presume that this relatively small congestion charge has transformed transport across London, because it hasn't. 

It claims that “peak car” is part of the phenomenon, which has an element of truth, but only in relation to trips into central London. If you map the congestion charge zone to the entire London metropolitan area (which for convenience sake I’ll say is the land within the M25 orbital motorway) then it is small indeed. On top of that, the actual amount of car travel into that zone was small anyway. Most commuting to central London is on public transport. Let’s not forget London has inherited over a century of development based around no less than 6 major and 7 lesser railway stations with lines radiating out from the centre, plus another 10 underground lines (most of which feed traffic from 2 directions) and most recently the Docklands Light Railway (more a light metro than a tramway). The capacity and usage of all of those outdoes all roads into central London, which includes only one grade separated highway from the West.

London simply never had a road network that could come close to competing with the rail and underground network in terms of travel times let alone capacity.

The congestion charge reduced car travel into central London by 20% from the start, but car travel represented only 30% of vehicle traffic in downtown London as it was. Buses and taxis command half of all vehicle traffic, and were exempt from the charge. When you count freight/delivery vehicles as around another 15% and then motorcycles, then cars have not been that significant for trips to central London. So to claim “many” Londoners have changed commuting habits is quite wrong.   

This figure below shows the small proportion of commuter trips to central London undertaken by car regardless, a figure that wont be easily replicated in almost any new world city.   It did drop from 11% to 7% (including private hire vehicles), but is completely dwarfed by the dominance of public transport modes.
Central London mode shares over 30 years showing decline in car trips
The story the further out you go is different. The car dominates outer suburb commuting and there is little sign that this will change. The reason is simple. Like any city, London’s public transport network is focused on radial trips and it’s very efficient at moving lots of people along those routes. However, for orbital trips it is slow. With the exception of those living and working along the single orbital rail route, or able to use the underground for a through trip (e.g. live at Cockfosters work at Heathrow) recently upgraded, those who live in the outer suburbs and work in the outer suburbs are unlikely to find suitable public transport options. Such jobs are also likely to have lower incomes than those in central London, so these car commuters are people of more modest means. This is the ignored group in transport policy in London. 

The report "Travel in London: Key Trends and Developments" states that whilst traffic to central London has declined, it has increased elsewhere, which is as much because pricing does not affect elsewhere (and alternatives are poor) as anything else.  
Traffic to central London has declined but outer London traffic has not
However, it is not as if congestion has been solved in London, far from it. For a start, it is such a small area that the positive impacts on congestion are mostly related to that area and some approach routes. Secondly, the Mayor who introduced the charge, Ken Livingstone, deliberately used the charge as a means to reduce traffic so he could reallocate road space for other purposes. This meant that, by and large, road capacity was reduced so that the net effect on congestion was minimal. New bus lanes, cycle lanes, footpath widenings and blocking some streets reduced capacity for other vehicles. That’s not to say that some of those moves were not wise, but it did mean congestion itself was still regarded as acceptable. 

Size of London Congestion Charging zone relative to greater London

Of course, you don’t need to go too far from the city centre to find chronic congestion to this day. Some of this is due to the surfeit of random bottlenecks on a road network largely unchanged for over a century, but overall it is because volumes have not significantly declined. Unless the congestion charge is drastically expanded in geographical scale, and with more disaggregated pricing by location and time of day, this wont change. In fact in some locations the problem is as much due to a lack of capital spending on fixing neglected bottlenecks as anything else.

So what about bus travel? That’s easy, the reason for this is a massive increase in subsidies and the resulting increase in routes and frequency of service (average wait time for a bus is just under six minutes for major routes during weekdays). Part of this was funded by the congestion charge, but most of it came from central government grants. A bus system that by and large broke even was by 2008 taking £750 million a year in subsidies. Since then, Mayor Boris Johnson has faced cutbacks in government spending so has increased fares to cut those subsidies by a third, with only a small reduction in patronage. In short, bus services were drastically expanded in frequency. Yet again, it would be a mistake to presume increased patronage came from car users, when in many cases it came from people who would have walked (as concession/free travel was expanded) or would have used the Underground (because buses are cheaper).  Passengers per bus average at 16.5.

Cycling has been a bigger success story, in part due to cycling lanes, in part due to it growing in popularity as a way to avoid crowding on public transport.   Average cycling flow are up 91%, admittedly from a low base, although demand is seasonal (winter usage is about 25% lower than summer).  Mode share increase is equal to a 13% drop in the proportion of car trips although nobody can be sure if there is a direct relationship.   A third of cycle trips are commutes, a quarter are leisure, shopping and personal business.


London's congestion charge has curtailed growth in traffic in central London and has resulted in capacity being relieved to then be reallocated to other modes.  However, by no means could anyone claim that congestion has been solved, or that central London has a good standard of service for road traffic.  It hasn't and it doesn't.  
London is a peculiar city regarding transport.  The car appears unimportant for most visiting central London and they'd be right, but for commuting in outer London, most likely undertaken by those on relatively lower incomes than those commuting into central London, the car is important, with a 56% mode share for such trips.   

The congestion charge would need to be drastically expanded to have an impact on such trips and to seriously address the chronic congestion in central and inner London.  That is not to mean what is there isn't useful.  It is.   However, let's not pretend that a small CBD cordon/area charge is the panacea for a city's traffic congestion problems.  It isn't, but it is a start.

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