A lot of UPS delivery vehicles have been coverted over to CNG.
Makes sense in at least some areas.
Gewehr98 -
I know UPS trucks(and other delivery vehicles) have some pretty long lifespans - but my point would be that there isn't any reason real why they couldn't start buying NEW UPS trucks in hybrid form. Whether that be for expansion or the occasional truck ruined in an accident. Heck, I even even expect them to look identical to regular ones, if maybe with 'Hybrid' decal somewhere so they can advertise their greenness. For that matter, with regular rebuilds it shouldn't take much more to convert them to hybrid at some point.
Found a link! Figure a 20 year average lifespan for an average UPS truck, I could see UPS starting up a few hybrid delivery centers - such as in California, actually shipping the older vehicles elsewhere to use, so they only have to have hybrid specific maintenance in one center. Once it proves it's long term cost effectiveness, roll out into more areas using attrition.
On the idea of a hybrid truck, I was struck by a thought. My new truck has a plastic bed, and there's plenty of room underneath the fairly high vehicle to have a sort of second bed with a layer of batteries. As a bonus, it'd lower the center of gravity and place a good deal of weight on the backside, increasing rear wheel traction for winter/ice, rather than having to use sand bags. On the drive side, I think that you'd probably find yourself still better off with a traditional traction system, though having an engine-generator under the hood, then one(RWD) or two(4WD/AWD) motors to provide propulsion might be an excellent solution. You'd get the same benefit a train has - absolutely insane amounts of torque at low speeds. Mated with an efficient 4 or even 3 cylinder diesel and you'd still have plenty of power to haul that 6k pound trailer.
Remember, as electric motors get smaller, they get less efficient. So you have to determine whether the energy losses from a driveshaft and differential exceed the losses from going to multiple smaller motors.
