From the web page for the above graphic:
The researchers at the Texas Transportation Institute have recently published new estimates of the effects of traffic congestion. Nearly 3 billion gallons of fuel is wasted each year due to traffic congestion. In 2007, the amount of wasted fuel declined slightly due to an overall decline in vehicle miles traveled when fuel prices skyrocketed. The wasted fuel amounts to 1.6% of total highway fuel use in 2007.
See the web page for a table of the data in the chart.
Using 20 pounds of CO2/gallon of fuel[1], this gives us 56 billion pounds of CO2/year from US congestion. This is greenhouse gas that we’ll have to live with and account for in climate policy for centuries. That’s a sizable cost to incur for no gain. I’d be hard pressed to come up with a better argument than this for adding start-top technology to new on-road vehicles that have internal combustion engines.
[1] For gasoline the figure is just below 20, and for diesel fuel it’s about 22 pounds, so using 20 pounds for a back-of-the-envelope number is reasonably accurate. On-road fuel usage in the US is roughly 2:1 gasoline:diesel fuel, but nearly all of that diesel fuel is used by long-distance trucks that encounter less congestion than the average daily commuter.
Well, hybrids and EVs should start pulling those numbers down before long.
Have we seen any production ICEs whose engines shut off and restart rather than idling yet? Or only prototypes?
Hybrids, and various flavors of plug-ins will help, but not for a while. Yearly sales are such a small portion of the rolling stock that it will take years to have any measurable effect.
As far as I know, there have been no start-stop equipped models sold in the US recently, but I’ve heard a lot of talk about new models with it. I’m pretty sure VW sold a car in the US with start-stop in roughly 1980/1981.