A bridge too far

'The Raft of the Medusa' by the French painter Théodore Géricault.

In an ABC interview  titled “Rising pedestrian deaths spark call for reduced speed limits, Peter Khoury ( a media representative of the  says:

“Pedestrian bridges, islands in the middle of busy highways – there is a raft of things that we can do to help keep pedestrians safe.”

The use of the word “raft” is especially telling. The NRMA acknowledges that pedestrians are on a flimsy raft in a sea of traffic, seeking refuge on an island while surrounded by a storm of high-speed cars who cannot be inconvenienced to slow down even in a city centre.

Unlike the sea on which we float waterborne rafts, the stream of traffic is well under the control of humans. The construction of high speed roads, and especially the implementation of traffic controls that restrict when and where pedestrians can cross streets can be seen as one more form of enclosure of public spaces. In history, the enclosure movement took the public commons and assigned it to private property owners. You can guess which property owners benefitted.

Traffic control took one of the last remaining commons, the street, and regulated and assigned it in both  a timeshare and a space share, where most of the time and space was allocated to the class of persons in vehicles, rather than those on foot. The term ‘jaywalking’ was invented in this period, as noted by Peter Norton in his well-documented history Fighting Traffic (which though American, is generally applicable to the Australian context, with a bit of a time lag).

What’s wrong with the NRMA proposal for pedestrian bridges?

Pedestrian Bridge The Boulevarde, Strathfield
Pedestrian Bridge The Boulevarde, Strathfield

The call for bridges is fine in a particular context, the context being the street or highway is depressed, so pedestrians are not required to ascend and descend stairs (or those less able or with strollers, to take a lift) to cross a street. An example is exiting Wynyard Walk, and approaching Barangaroo, the pedestrian bridge over Sussex Street. The pedestrian is already elevated on one side, so continuing the elevation serves rather than punishes the pedestrian. Otherwise it is yet one more insult to pedestrians who once roamed freely, not inconvenienced by cars. An illustration is at the pedestrian bridge from Strathfield. I am sure having children at the adjacent school not get hit by cars is the nominal justification for the bridge, but are there perhaps other designs that can be used to achieve that end.

Similarly, airy, well-lit, non-malodorous tunnels and underpasses are fine under elevated roadways, so long as the pedestrian need not descend to the fiery pits in the depths of hell to cross a motorway.

But we should not think of bridges as costless. A pedestrian bridge is expensive, (the City of Atlanta Georgia spent $23 Million (US) to build an urban pedestrian bridge for Mercedes Benz football stadium, obviously, costs will vary with the scope of the project.).

A bridge is certainly more expensive than paint and changing the signal timings and speed limit reductions.  As the adage goes, organisation before electronics before concrete. And traffic control and speed limits are very much organisation and electronics.

So for Benefits to exceed Costs, we must rely on time savings (multiplied by the value of time) for car occupants exceeding  the added travel cost for pedestrians and the cost of the bridge. This is seldom the case (it’s not like a pedestrian bridge solves the problem of cross-traffic). Benefits > Costs is not the only test however, the bridge alternative must be better than the next best alternative like regulatory and control changes. This is even less likely to be the case.

It is, to be clear, not mostly a question of costs. It is a question of values: what kind of place do we want?

While some transport agencies act as if pedestrians are allowed to cross roads at the sufferance of traffic lights designed to serve cars, their logic is backwards: Cars exist at the sufferance of pedestrians.

We know this as all of us are walkers in some form or another, and not all of us are motor vehicle users. The pedestrian has precedence historically.

So we should be thinking about not where pedestrian are permitted, but where cars are. And like shopping malls, parks, and university campuses, city centres and shopping streets seem good candidates to prohibit cars. Where they remain, they do so at the sufferance of pedestrians, and need to stop when pedestrians need to continue on their right-of-way.

What’s wrong with the NRMA proposal for islands in the middle of highways?

I wrote about the problem with refuge islands earlier, See: Sydney’s Refugee Crisis.

At least 20 people, most of them children, queued up like bowling pins, on a refugee island at City Road and Cleveland Street, Sydney. Other groups are held back at the Seymour Centre, or have been already ferried across City Road to Victoria Park. This is typical, but not good, urban design.
At least 20 people, most of them children, queued up like bowling pins, on a refugee island at City Road and Cleveland Street, Sydney. Other groups are held back at the Seymour Centre, or have been already ferried across City Road to Victoria Park. This is typical, but not good, urban design.

Crossing the street half-way, and waiting on an island is not the kind of pleasant experience we think about when we want to enhance walkability, which last I checked was still a stated goal by just about everyone who is not the NRMA.

Standing on an island in the middle of the road:

  • increases exposure to danger (cars are approaching both in front and from behind),
  • increases exposure to pollution (there is no more polluted location than the middle of the street),
  • increases delay compared with giving the right-of-way to cross to pedestrians, and
  • increases exposure to noise, which is a serious and under-rated problem in the urban environment.

But by saving cars a few seconds, it makes driving that much more convenient, and thereby increases the number of cars on the road overall. If the street is too wide for the pedestrian to cross in a single movement, perhaps it is too wide.

Unfortunately, the NRMA cannot abide lowering speeds, reducing both likelihood and severity of impact. That is apparently a bridge too far. Their life-raft is like that painted by Gericault, which Wikipedia says:

[D]epicts a moment from the aftermath of the wreck of the French naval frigate Méduse, which ran aground off the coast of today’s Mauritania on 2 July 1816. On 5 July 1816, at least 147 people were set adrift on a hurriedly constructed raft; all but 15 died in the 13 days before their rescue, and those who survived endured starvation and dehydration and practised cannibalism. The event became an international scandal, in part because its cause was widely attributed to the incompetence of the French captain.

Sydney’s walkers, and those everywhere, deserve better than a cobbled-together raft.

Published by David M Levinson

Prof. David Levinson teaches at the School of Civil Engineering at the University of Sydney, where he leads TransportLab and the Transport Engineering group.

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