Transportation modeling provides us with a means for examining different futures. But is it . . . science or is it art?
Robert Bain asked this question to a British academic transport list (UTSG) last week and got an interesting range of responses which he has written up with an analysis and commentary. He added to his invitation: “If you’re inclined to expand on your view(s) I’d be delighted to read your thoughts. Similarly, any references to articles or papers that touch on this issue would be gratefully received.” (Likewise here.)
However if you forgive me, we will not point you to his write-up until we have completed this little survey, the results of which will be conveyed to him and will also appear as part of an article here in these pages next week. (To contact Robert Bain concerning his poll: info@robbain.com and www@robbain.com)
In the meantime, here is our poll (including with the interim results.). Thanks for taking literally one minute to fill it out. And for commenting (see below for comments to date).
WORLD STREETS __ A New Mobility Action Plan for 2022 
The Chartered Institute of Transport which I joined as a Student Member in 1957 existed “to promote the science and art of Transport in all its forms”. It is now the Chartered Institute of Logistics and Transport and covers the whole of the United Kingdom as well as most British Commonwealth countries and others.
There is nothing new in the world!
My immediate response is it is probably : “A bit of both”, but the problem and what is important is that is is partly _bad_ science. Or at least science in need of fundamental rethink.
It appears that when modellers predict endless growth in traffic, they have certainly not taken all the boundary conditions into considerations. Nor do they present different scenarios, or hint of the existence of phenomena like traffic evaporation.
Traffic evaporation has been observed repeatedly I’m told when access for private cars has been limited. Probably in most cases other options, like cycling, ride-sharing and public transport have been available.
I attended a couple of presentations on transport modelling a few years ago. I have already concluded that transport modelling is neither an art nor a science, but a money making exercise. Transport models rely on traffic counts and estimates of future demand for road space by cars and commercial vehicles, including buses. This data is entered into a computer and combined with information on the streetscape to produce some very exciting graphics that wow decision-makers – and often recommend traffic lights and huge, land consuming junctions.
The data used in the UK, is incomplete. Only recently have transport modellers started to consider cyclists and pedestrians, and data on cyclist and pedestrians movements (which they do not understand) are only added to optional modules at the end of the process.
Some simulations from transport models can be found on Youtube. If the simulated streets have any pedestrians, they have the movement of statues.
See: http://www.youtube.com/watch?v=2nW4i3mJvqw
and: http://www.youtube.com/watch?v=sBFcdGNLRdQ&feature=related
-quote: “The Traffic Group, Inc. has had tremendous success using simulation technologies before Planning Boards, citizen forums and review agencies. These models help visualize traffic operations and actual site impacts. The model is also vital in evaluating operations of access points and/or proposed road improvements in before and after scenarios.”
Travel time determines many travel decisions, and by increasing road capacity to reduce congestion, as we have seen so many times, the resulting time savings result in more people using the road, until congestion (and time) again controls journey numbers. Street space should be designed for people’s amenity and pedestrian movement followed by cyclist movement and the remaining space offered to service vehicles, public transport and any remaining space made available to private vehicles. If there is a transport model that does this, it is seldom used.
Transport models can be used to produce great looking 2D and 3D simulations, but there is significant evidence that the data is flawed and biased towards motorised vehicles.
On the one hand transportation modeling is supposed to heal an ill from driving. On the other hand it proceeds to inflict additional harm or damage upon members of a community or their property who are not aligned with driving. And the science is dodgy at best as Shoupe showed in the High Cost of Parking. So its witchcraft.
In via Facebook from Free Public Transit Editors: http://www.freepublictransit.org
As long as the auto system is propped up by trillions in subsidy, planning is impossible — and irresponsible.
The following film from Australia (though relevant worldwide) is very enlightening on the views of transport engineers, and shows how little they/we have changed since 1999: