<html> <body> 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 <a href="http://www.vtpi.org/wwclimate.pdf" eudora="autourl"> http://www.vtpi.org/wwclimate.pdf</a> ). Best wishes, -Todd Litman At 10:42 AM 5/6/2007, Martin Cassini wrote: <blockquote type=cite class=cite cite="">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</blockquote> <x-sigsep></x-sigsep> Sincerely, Todd Alexander Litman Victoria Transport Policy Institute (<a href="http://www.vtpi.org" eudora="autourl">www.vtpi.org</a>) litman@vtpi.org Phone & Fax 250-360-1560 1250 Rudlin Street, Victoria, BC, V8V 3R7, CANADA “Efficiency - Equity - Clarity”   </body> </html>