Quantifiably faster than any other city of 6-million+

It is based on travel time surveys that we “know” people commute 27 minutes each way in Dallas-Fort Worth, 37 minutes in London, and 42 minutes in the big Asian cities like Tokyo, Hong Kong and now Singapore (a chart and stats here). Those are all cities in the 6-8million category where you can’t cycle uninterrupted because of all the transport machines in your way. I would like to know what the average commute time would be in a city of 6 million people, without the machines in our way. If all of us were on bikes, and the ground plane was very permeable (chamfered corners, short blocks, some piloti) I’m assuming we could make virtual beelines to our destinations without ever touching our brakes. That just leaves the question of distance.

You may have heard me say this before, but a 15 km diameter circular city with the same number of people per square kilometre as Manhattan (30K) would have 6 million people. So let’s say this imaginary circular Manhattan had a permeable ground plane and no cars. What would be the average commute time for people on bikes making near-beelines and cruising at a constant speed of 15kph?

dislinpk (1) 2

This leads us to a maths question that I am able to answer because my brother-in-law is a physicist. We want to know the average distance between any two randomly chosen points on a 15 km diameter disc. The technical term is “disc line picking“. If you are my brother-in-law you will be able to work it out this way and even generate some sweet drawings:

Or if you are more like my lazy mate who I went to school with, or Edward from Bike Adelaide who helped out as well, you would just plug the r (radius) value into this formula you found on the web:

d = 128r/45π

Either way the average distance between any two points (people, jobs, schools, shops etc) in this imaginary city of 6 million people is 6.79km. Beelining bikes doing 15kph will cover that distance in 27 minutes and 9 seconds (you gotta be precise once you start playing with maths).

Oh boy! That’s the exact time residents of Dallas-Fort Worth are claiming to average when they complete their travel time surveys.

You may say bikes can’t go as the crow flies, even in a permeable city, so let’s round 6.79 up to 9km. But that figure needs rounding down by a third. Transport geographers talk about the need for two thirds of a city’s jobs to be within striking distance of each resident’s home—not the whole lot. And you know yourself that, given a choice, few would take the job on the opposite side of town in preference to one that is nearby.

So our average commute distance is 6km, which 15kph would take 24 minutes. At 20kph (the speed Copenhagen’s cyclists are encouraged to maintain to catch all the green lights rolling into the city) it would take 18minutes—substantially less than Americans commute on their kazillion dollar road networks. Am I wrong that the fastest city imaginable is permeable, as dense as Manhattan, and completely car free?

So I have just drafted a cover blurb for this book I am now preparing to send off to the editors. What do you think?

Not since Le Corbusier gave us his Radiant City has an architect presented such a thoughtful yet daring vision for how cities might be. Instead of modelling big new cities on little old ones, then plugging them full of machines to help them expand, author Steven Fleming outlines a hypothetical model designed from the outset for bicycle transport, and little else. It is “less, but better”—to quote Dieter Rams. 
Unlike books that approach urban cycling from a sustainability standpoint, Velotopia takes the moral low ground. It is taken as given that our mode choices are determined by the design of our cities, and that cities are designed to make us all money. The city we want (and that five billion people emerging from poverty likewise desire), is the one that connects us to the largest markets in the least time. In the six-million-plus population category, cities like Dallas-Fort Worth have been winning this game, and thus serving as models for the developing world.
That was until now. Using analogies, diagrams and a good dose of humour, Fleming explains how six-million people could all get to work faster if their cities were designed around cycling. Once the model, its innovative new buildings and its relation to architectural issue have all been outlined, it is time to show how the new development paradigm might work in actual cities. It should be more like wax in a lava lamp than ink in water. A picture emerges of industrial wastelands being redeveloped into beacons of change, not only for those living in car-land, but for a planet in a race to build cities.