Comments on: The Key to Countering Turbulence: More Turbulence

By: Sandeep

Sandeep — Sun, 28 Mar 2010 14:10:32 +0000

Although pedestrian traffic is slightly different, I’d expect the same as vehicular traffic or even worse, a stampede

By: Sandeep

Sandeep — Sun, 28 Mar 2010 14:06:49 +0000

Tom, your blog has many interesting things and I keep reading it from time to time.
About this post, the research on Dr. Hof says,
“…it’s pushed along by smooth-flowing fluid behind it…”
“…Dr. Hof and his colleagues realized that introducing an eddy into this smooth-flowing zone would eliminate the turbulence in front of it…”
Vehicular traffic flow is likened and sometimes modeled using some principles from gas flow. But the key difference is that traffic flow is anisotropic i.e. a vehicle does not respond to conditions behind it but only in front of it. Imagine a congested stretch of a roadway. Now if there is a free flowing traffic behind it, what would you expect ? The vehicles in the smooth will also enter the congested regime unlike a gas flow where the flow from behind pushes the gas in front of it.
Thanks for posting though

By: Mike Chalkley

Mike Chalkley — Wed, 24 Mar 2010 09:31:47 +0000

Tom, not completely on topic here but relevant to the issues you deal with… Have you read ‘Death on the Streets’ by Robert Davis (isbn 0-948135-46-8)? A fascinating essay on how cars & roads in the UK have contributed to a lot of the social and safety problems we now face.

One of his central points is that the seat belt laws here have resulted in drivers ‘risk-compensating’ by driving faster instead of safer. This results in no net safety benefit for car occupants and hugely increased risk to vulnerable road users.

I couldn’t remember if you’d mentioned his work in Traffic (I’ve lent it to my neighbour – a local council traffic planner – so I can’t check!). If you haven’t read it – DO! It’s an eye opener and poses the worrying point that if we don’t do something drastic about cars like making them fully automatic, we will continue to suffer from the carnage and car-centricity we currently have on the roads.