Traffic engineers and their idea of "capacity"

The green and yellow roads on this map are arterial, and designed to maximise traffic capacity. I can accept that. There are almost 6 million people in Singapore and almost 1 million cars. If both figures grew ten-fold, the cycling agenda might thrive just as well. And if there were 60 million inhabitants, then maybe 10 million driverless taxis, speeding around with no braking distance between them, all centrally controlled by computers, would be exactly what those 60 million people would like to see filling their arterial roads.

My concern is that active transport has a chance to compete, and show itself to be better. That requires an alternative network of bike-superhighways, away from the car fumes, and a road engineering approach that treats residential neighbourhoods as havens from the busses and lorries (or even the Johnny Cabs) that might one day pack the main roads.

I was part of a community forum today investigating the impact of a one-way ring road, with no arterial function, that runs within the residential district of MacPherson in Singapore. Inside the ring, there are public housing blocks and lots of people walking and slow-cycling. All those people need to cross the ring road to get to the shops, schools, and bus stops. A recent accident involving a school boy and truck proved what a lethal situation exists here, and the forum I was part of today proved just how monotheistic is this religion, called traffic engineering. Traffic engineering departments serve one god, and one god alone, and His name be “Capacity”. This ring road dividing a community could be built in materials that remind drivers they are entering a big outdoor living room, but the attitude of the traffic engineers is that such measures would reduce the overall “capacity” of Singapore’s network of roads.

This idea that residential streets should add to vehicular capacity misses one vital point. The islands between the arterials roads, are where people live, on foot and on bike. The capacity that matters, is peoples’ capacity to cross the road safety and freely, on foot and on bike. So I’m wondering if any of Hans Monderman’s thinking is taught in schools of traffic engineering? He would use devices like this to let drivers know they are entering somebodies playground:


  1. Colin says:

    Capacity for what? Traffic? What does that include? Cyclists? Pedestrians?
    If you ban cars from a street you surely raise its traffic capacity enormously.

    • Steven says:

      That’s true, but Singapore has a Jetsons vision of cars and skyscrapers, deep in its national psyche. It’s emerging nation affliction, like handbags and shoes

  2. William Benson says:

    What an active area that last photo shows – clearly a major win of urban design over traffic engineering… But seriously – I wonder if the hopscotch markings ever get used? Are parents still reluctant to let their children play on this street despite its ‘softer’ engineering?
    I do like however how the rocket looks like a ‘full steam ahead’ arrow for car drivers directing them down the straightest path of the street. Nice idea – poorly executed.

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