Frankfurt Maths 2: A cunning marketing scheme (and/or a way to massively inconvenience the disabled)

If you’ve spent more than about seventeen seconds in Frankfurt, you’ll have met the Escalator Fairy: the strange malevolent force that ensures that there will always, always, always be at least one broken escalator between you and your destination – more if you’ve got heavy suitcases or are travelling with someone who has a disability.

But even when they’re working, the escalators in Frankfurt can be a source of limitless irritation. Not too long ago, Dove’s family came to visit, including her granddad, who needs a walking stick. We had to get a replacement battery for a mobile phone (or as the Germans would say, EIN HANDY AKKU) so we decided to go to the Saturn in MyZeil, the topologically non-trivial shopping centre on the Zeil.*

Because of its odd shape, MyZeil has an odd system of escalators, including what is supposedly the longest escalator in Germany. (My copy of Inkscape isn’t working, so you’ll have to make do with terrible Microsoft Publisher illustrations instead).

The pre-Christmas arrangement

This is how they used to be set up. It’s a good system – from any point to any other point, the shortest route always involves just one stairwell of escalators (escalatorwell?).** Great for customers… not so great for sales. With this escalator arrangement, people walk past very few stores – they just go to the escalators from the entrance, and then go straight to the floor they want.

Plus, the way escalators are arranged mean it can get quite congested – from the bottom of an escalator, it’s often not clear which way you have to turn to find the next one going your way, which means lots of people dillydallying around blocking other and causing accidents.

Last Christmas, the managers clearly decided that this arrangement just wasn’t good enough. So, let’s look at a higher throughput arrangement.

High-throughput escalator layout

So, this is how they could have decided to deal with the Christmas rush. One escalator well dedicated to upwards-bound flights, one to downwards-bound. Because there is only one escalator well to the 4th floor, that one would remain alternating. This one slightly increases the distance people will have to walk – you can no longer always take the nearest escalatorwell – but it would also reduce the number of queues to use the escalators and hopefully even out the traffic loads between the two sets of escalators.

But that’s not what they went with either. They went with this diabolical layout:

Evil.

From a marketing perspective, this is the perfect layout.*** If it’s not clear how annoying and devious this layout is, here’s a diagram showing the shortest route from Saturn, MyZeil’s biggest “anchor store“, to an exit:

Look at that.

The yellow arrows mark the route that we would have taken with either of the other suggested escalator layouts. The orange arrows mark the huge detours we had to take right through MyZeil just to get to the nearest exit. To get out to Zeil, we’d have had to go even further:

The long walk

You have to walk almost three times as far with the diabolical escalator layout, on a route that takes you past almost every shop in MyZeil. From a marketing perspective, it’s genius – any customer who goes into MyZeil is forced to go past most of the businesses inside, but in doing so, they have to walk much further than they otherwise would. It’s a petty problem, sure… unless you’re with someone who has difficulty walking. Say, someone with two artificial knees who needs a stick. In which case, it’s not just a petty inconvenience, it can cause them serious difficulties.

Screw you, MyZeil.

* Unlike most buildings, whose exteriors are homeomorphic to a sphere, MyZeil is homeomorphic to a genus-2 surface.

** With the exception of the route from the ground floor to floor 5, but there’s just a children’s restaurant up there.

*** There is one layout which would be even more annoying:

In this design, all the ground floor escalators run up only, trapping unsuspecting customers up there. To get down, customers have to go all the way up to floor 4 (and because the external escalators between 3 and 4 run down only, they’d have to go into Saturn and use the escalators inside there). However, this would mean putting four floors worth of shoppers onto one escalator, which would be a recipe for disaster. MyZeil won’t be using this one yet, at least.