Monday, April 27, 2009

The London underground tube is too slow

I've been ranting a lot lately but I think today's topic is a good one.

In 2007 approximately 1.1 billion journeys were taken on the tube. The people on the tube are some of the most powerful and productive in Britain who contribute massive amounts to the economy.

However whilst Livingstone and Boris have promised upgrades to the tube, rarely do they address, what is for me, the biggest priority. Speed.

Certainly if you play with TFL's journey planner you'll be forgiven for thinking all is well. But the journey planner significantly underestimates the time trips take and always assumes buses run to schedule and the tube "average journey times" are extremely optimistic and do not include the time it takes to get from the platform level to street level, which can add several minutes.

Lets take for example a trip from Notting Hill Gate at the western edge of zone one to Liverpool Street which is near the eastern edge using the central line. According to Transport for London's journey planner you can do the journey in just 18 minutes. It is 11 stops along. This means that the train can take no more than 1.6 minutes (or 1 min 36 secs) to travel between each station and offload and pick up all the passengers. Dream on.

So realistically lets say that the journey could be done in 25 minutes, allowing 2.2 minutes (or 2 mins 12 secs). The walking distance between the stations is around 5.4 miles according to Google Maps (if you want to repeat this experiment).

So if we take TFL's estimate of 18 minutes over a distance of 5.4 miles gives an average speed of 18mph (though you would need to factor in stopping times to be fair, in which case (allowing 30 seconds per station) the speed is 18 minutes minus 5.5 minutes equals 12.5 minutes. The distance is 5.4 miles. So distance divided by time gives us a speed of 25.9mph.)

Using the realistic times 25 minutes - 5.5 minutes = 19.5 minutes. This gives an average speed including stops of 20.9mph

Once you factor in the waiting times, train changes, walking down to the station level and up to street level, getting through the barriers, buying a ticket and any other inconveniences your average speed is going to be very low indeed. TFL hopes that we don't realise just how slow we are going. It is simply the short gap between each station that creates the illusion of speed.

If TFL increased the average tube speed they could have greater capacity and improve the London economy because if everybody saved 5 minutes on their commute (10 minutes daily), in a 310 day working year that's an extra 3100 minutes, or 51.666 hours, or to put it another way, an extra day at work and an extra day at home with friends and family, with a couple of hours left over to grab a drink and read the paper.

Multiply that by everybody using the tube and suddenly the arguments become very compelling indeed.

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