Saturday, 5 December 2015

Speedy boarding on the Tube: stand clear of the doors

Ever jumped through the Tube doors as they're closing? Yeah, me too. We're all at it. "In London we tend to think of the doors closing as a challenge not a threat," said Nick Tyler, professor of civil engineering at UCL.

Tube doors cropped up in The Art of Boarding and Alighting, at the Institution of Mechanical Engineers. Nick's helping Transport for London (TfL) work out how to get people on and off trains quicker.

Faster? No!

We commuters already move as quickly as we humanly can. "It's very hard to get people to go any faster. People move at a certain speed and it's very difficult to change," said Nick. So TfL is turning to engineers and human factors experts to supercharge us.

Wider doors

You could make Tube doors wider. You could redesign Tube carriages getting rid of the end-of-carriage single doors and make all doors double. But it takes time to redesign.

Pillars and zips

Another trick for getting crowds of people to move forward efficiently is, believe it or not, to put a pillar in front of them. "A pillar acts like a zip, it forces the crowd to split to go round it. In Oslo trains have a central pillar," explained Nick.

But again, that would be a redesign. And pillars take up space.

What's the frequency, Kenneth?

But in the meantime, there's an obvious solution: increase the frequency of Tube trains and that increases the number of people you can ferry around. "You could have the next train coming as the current one leaves," said Nick.

To increase frequency, you need to reduce 'dwell time' in stations.

Automatic (for the people) doors

And to reduce dwell time, said Nick, TfL probably needs to change the way the doors operate. At the moment Tube drivers decide when to close them. And we, the passengers are constantly rushing on at the last minute and holding up the train.

27 seconds

It may be more efficient to have Tube doors that close automatically after a certain amount of time. Automatic doors can help you regulate frequency, run a consistent service.

For Thameslink, Nick's team built a full-size mock-up of a train and paid people to act as rush-hour passengers. The experiments found the most efficient amount of time to get enough people off and on the Thameslink train was 27 seconds.

Any longer and Thameslink wouldn't be able to run frequent enough trains for the number of passengers it expects to carry. Nick emphasised that 27 seconds was chosen for Thameslink - but the most efficient dwell time depends on the design of train.

Stand clear of the doors

But the big question is how you stop Londoners like us from charging onto the train just as the automatic doors are closing? One way of changing our behaviour may be to give us more information about the next train: "The next train's one minute away and the back 4 carriages are far less crowded than this current train".

And that information needs to reach us at the place we need it - either audio from the tannoy or by projecting a message onto the space we're gazing at when trying to pile on a train.

And to help us get off the train more efficiently, we need information about the approaching station: "Doors will open on the left. The platform's crowded so ...."

Mind the gap

Boarding and alighting times are not the only thing on Nick's plate. Other issues include helping us mind the gap.

Ironically a small gap can be worse than a big one, as we're less likely to notice it. A future project would be to design a shelf to descend from the train doors to match the level of the platform. An extra engineering challenge is London's Victorian curved Tube platforms that make for a quirky platform-train interface.

Tiny tip: how to simulate rush hour

When simulating rush hour, you can motivate participants to charge onto a prototype train by paying them extra if they manage to get a seat, admitted an industry insider. Rather like musical chairs.

No comments:

Post a Comment