[sustran] Re: Fuel consumed by idling

martincassini at blueyonder.co.uk martincassini at blueyonder.co.uk
Thu May 10 18:54:26 JST 2007


I thought I said, and meant, that 40% of polluting gases from traffic, not
fuel used, is from traffic idling. I got that figure from pro-regulation
man Prof David Begg. As you might have read, chronic lung disease and
malformations occur in children who live on or near main roads. My lung
function has suffered since I moved to King's Cross. On the Euston Road, I
see catastrophic congestion every day of the week, caused largely by an
endless procession of mandatory traffic lights, permanent bus lanes, and
the congestion charge which forces vehicles on to outer routes.
>
> Please cite sources for the claim that 40% of fuel is used from
> idling. I suspect that it is a misinterpretation of the data. A
> typical vehicle consumes about a tenth as much fuel per unit of time
> while idling as under load (typically about 1 liter per hour for a
> car and 2 liters an hour for a large truck). If an average vehicle is
> driven 1 hour per day and idles 5 minutes, idling represents about 1%
> of total fuel consumption.
>
> I think Cassini may be confusing idling with stop-and-go driving
> conditions, but I'm skeptical that the traffic management strategies
> he advocates would actually increase traffic efficiencies. I think
> there is a good case for converting stop signs and signal
> intersections to roundabouts, but I've yet to see evidence that
> eliminating traffic controls altogether ("naked streets") reduces
> delay or crash risk overall in most situations.
>
> There are many anti-idling campaigns underway, but most seem to
> exaggerate the benefits, they are an excuse to avoid the more
> critical reforms needed to reduce economically excessive vehicle
> travel and associated social costs (see http://www.vtpi.org/wwclimate.pdf
> ).
>
>
> Best wishes,
> -Todd Litman
>
>
> At 10:42 AM 5/6/2007, Martin Cassini wrote:
>>Dashing out, but in the UK, about 30% of our CO2 output is from traffic.
>>Prof David Begg admits that 40% of that is from traffic idling. How
>>often does traffic idle at lights for no good reason? I live in King's
>>Cross, and I would say a good (or bad!) half the time. Also you have to
>>add the cost of manufacturing, installing, maintaining and RUNNING the
>>galaxy of 24-hour lights - this alone represents a massive carbon
>>footprint. If it wasn't for the lights, traffic would filter and flow,
>>instead of continually stop, idle and re-start. Traffic volume can be a
>>drama, but volume + controls = crisis.
>>
>>Martin
>
>
> Sincerely,
> Todd Alexander Litman
> Victoria Transport Policy Institute (www.vtpi.org)
> litman at vtpi.org
> Phone & Fax 250-360-1560
> 1250 Rudlin Street, Victoria, BC, V8V 3R7, CANADA
> "Efficiency - Equity - Clarity"
>
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