United Parcel Service is putting more of its quiet hybrid diesel/electric trucks in South Philly's Oregon Ave. depot than anywhere else in the U.S. 50 of its 200 new hybrids were scheduled to roll out here today, more than are going to Chicago, Washington, Minneapolis, Austin, Houston, or the New York area.

Why here? Because "the stop/start nature of Philly driving routes" makes Philadelphia the "most effective" place for the hybrids, according to UPS. We have the right mix of brake-tapping Center City crawl and expressway-exit snarl. The new trucks' "regenerative" brakes are hooked to reversing generators that are supposed to recharge the battery as the driver presses to slow down.

UPS delivery trucks burn roughly 2,500 gallons of diesel a year, Robert Hall, the company's director of maintenance and engineering, told me. The company figures it can chop that by one-third with the hybrids.

The trucks look like conventional brown UPS diesel delivery vans. They're built by Freightliner Custom Chassis Corp. in Gaffney, S.C., and assembled at Utilimaster Corp.'s Indiana Plant, with Eaton Corp. hybrid power systems and lithium-ion batteries.

The company previously deployed 50 earlier-model hybrids in Southern cities. Manhattan isn't getting any of the latest model: "New York's very different. Those high-rise stops take a very long time," said Hall. It's cheaper to turn those trucks off.