Wednesday, February 16, 2011

Record London Transport Use

The number of people travelling on London's Tube and bus service will hit an all-time high of 3.4 billion a year, the Standard reports.

Which raises the question of how the public transport network will cope, given funding constraints.

One way the network can cope better is by making more efficient use of roadspace. Right now, congestion charge aside, it's a free-for-all, and the congestion on the roads is caused by low-occupancy, large-footprint vehicles, by which I mean vehicles that takes up a lot of roadspace relative to passenger numbers. A bus, assuming a good load factor, makes good use of roadspace because although it is large, it has a lot of passengers. The same is true of trams. Although a cycle is a single-occupancy vehicle (most of the time), it requires relatively little roadspace, so again, it is efficient. At the other end of the spectrum, you have cars and taxis. A fully-loaded taxi carrying five passengers is a reasonably efficient use of roadspace, but typically the load factor (i.e. number of passengers) for London taxis is close to 1, making them low-occupancy, large-footprint. Cars are the least efficient: again the typical load factor is close to 1. (I'm only considering passenger vehicles here: goods vehicles are another discussion).

A good business person will strive to do more with less: to make more efficient use of their assets, and to deploy them more effectively. In road transport terms, to do more with less means increasing the average occupancy per unit of roadspace, while not increasing journey times.

If road congestion is reduced, buses run faster, and each bus can make more journeys, increasing revenue, average fuel consumption goes down and the passengers get to their destinations faster. Happy days! Buses can't get around quickly if the bus lanes are full of stationary taxis, which is the case on The Strand pretty much every day. To make bus journeys faster and more efficient, you need to get the low-occupancy, large-footprint vehicles out of the way: in other words, prioritize buses over them.

Cycling also makes very efficient use of roadspace. Not only do you get around 7-10 times as many cycles per square metre of roadspace than motor vehicles, but cyclists can use backroads without causing noise and air pollution or significantly intimidating pedestrians. When motors use backroads, it's called rat-running, and it significantly degrades neighborhoods, causing noise-nuisance and danger. It damages businesses too - no-one wants to have dinner at a cafe where there's noise and diesel fumes. Cyclists can get through bottleneck junctions much more effectively than motor vehicles.  You could increase the number of cyclists on central London streets by an order of manitude using existing roadspace: it would be impossible to increase the number of motors without massive cost, and at the price of degrading Londoners' quality of life and making the city a lot less pleasant for visitors.Therefore, it makes sense to encourage cycling as a way of leveraging existing roads more effectively: however, this is difficult to do when the presence of motor traffic pretty much everywhere is discouraging people from cycling.

There are some pretty stark choices facing us in London. Right now, there are few controls on low-occupancy, large-footprint vehicles, and London is a congested city because of them. The ubiquitous presence of motor traffic is sufficiently intimidating to force many people not to cycle, which puts a greater burden on the bus and tube network. But buses are made slower and more expensive by congestion. In an ideal world, with unlimited space and money, we could build more roads and everyone could drive everywhere. In the real world, we've got a choice between allowing the choices of a very few people to damage the smooth, efficient running of the city's transport, or to start making the best use of the resources and roadspace we've got.


  1. You say that taxis have a load factor of not much more than 1 - actually, it is probably less, because a large proportion of taxis at any one time are plying for hire - driving around passenger-less looking for a fare. So in fact their footprint is huge, which adds insult to the injury of their shocking PM10 pollution record which Boris has more or less abdicated responsibility for by cutting down their emmisions inspections.

    At least Boris seems to be quietly dumping his idiot commitment to electric car charging - they will occupy just as much space per passenger as a petrol car, be just as dangerous to vulnerable road users, and actually they pollute just as much - it is just that it is the neighbours of Didcot or Drax B who have to put up with it. It is complete baloney to imply that they can be fuelled by renewable energy - there just isn't enough renewable capacity to meet ordinary domestic demand let alone transport.

    And these wonders were going to get unlimited recharges for £100 a year!

  2. @Paul M,

    You're right. The load factor can indeed be BELOW 1. I had not realized that.

    If a taxi has 1 passenger, load = 1. When the taxi is cruising without passengers, they are not transporting anyone, load = 0. If the taxi has to drive even a little to get another hire, the average load factor will drop below 1, even worse than a car.

    So unless taxis can get many hires with more than one passenger, or they can avoid riding empty, they are not really reducing congestion at all. They might even make it worse.

  3. To be fair to taxis, they would be a juicy target for rechargeable hybrid vehicles. The taxi stands could offer charge points (somehow authenticated and billed against specific vehicles), so time spent sitting waiting for passengers would charge them up and so reduce their operating costs. It makes a lot more sense for the government to subsidise hybrid taxis than short-run electric commuter cars that only do a few miles every day.