Fellow geek driver C sent this my way, evidently having missed my April post on the same topic:

Left-Hand-Turn Elimination

It seems that sitting in the left lane, engine idling, waiting for oncoming traffic to clear so you can make a left-hand turn, is minutely wasteful — of time and peace of mind, for sure, but also of gas and therefore money. Not a ton of gas and money if we’re talking about just you and your Windstar, say, but immensely wasteful if we’re talking about more than 95,000 big square brown trucks delivering packages every day. And this realization — that when you operate a gigantic fleet of vehicles, tiny improvements in the efficiency of each one will translate to huge savings overall — is what led U.P.S. to limit further the number of left-hand turns its drivers make.

Earlier this year, I humbugged this as a drop in the bucket compared to greater gains that UPS could achieve with more extensive and expensive innovations. Some interesting things have changed since then.

The first piece I noted in Time magazine, said the no-left-turn program had saves 1,000 tons of carbon in the greater New York area in a couple of months. The NY Times piece above says that they’ve reduced by 31,000 tons already. Hard to compare. BUT, back in April the price of a ton of carbon offset on the Chicago Climate Exchange was around $3.70, and today it’s down to about $2.00.

Maybe I’m figuring this wrong, but I find it hard to see how a $62,000 savings by an outfit as large as UPS even covers the cost of equipment and programmers to figure out how to save that carbon. And what does it mean that the price of carbon offsets is down so much since the spring? It makes me wonder if the carbon trading thing is working. (At least in the short term, the idea would be to make emissions credits expensive enough to change behavior, and a drop in price would seem to indicate slack demand, so either everybody has already gone green, or nobody is paying much attention…)

Let’s take a different tack: if UPS trucks and only UPS trucks can save 31,000 tons of carbon making fewer left turns, why not make every driver (or at least every truck driver) follow the same rules? What if local traffic planners took UPS’ data model and used it in planning light timing and intersection design and all that? What if GPS units and online map programs could be programmed for “greenest” route instead of “fastest” or “shortest”? If UPS trucks are 10% of all trucks (seems a high estimate to me), we could end up saving 310,000 tons of carbon this way, or if we add cars into the mix, maybe twice that!

If you live in a city modern enough to have the luxury of choice between three rights and one delayed left, consider this modest proposal. As Confucious said, “A journey of a thousand miles begins with a single step.”