CONSIDERABLE SHOUTING said:
Probably unable to be used during winter unless the USPS provides serious winter exposure gear (which they might, depending on how much they save).
That would depend entirely on your local winter weather. Places like the Southwest USA would be better suited to using these *in* winter, but not necessarily in summer (for instance, here in Phoenix, AZ, with 110-120F+ temperatures, and often little or no breeze during midday/early afternoon as the winds begin to shift directions as the city heats up, unless at least basic cooling systems can be implemented.
Probably not able to carry serious packages, thus requiring a vehicle and potentially defeating the purpose.
That would depend on the assist system. For instance, with my SB Cruiser trike and the bigger MkIV.5 trailer, I have hauled about 600lbs of dog food in one case, and an upright piano in another. If the trailer were built as a bigger reconfigurable box (the MkV will be, if I ever need it enough to make it), then I could carry quite a bit of stuff, including some stuff that would be equivalent to larger packages.
I'm sure a system designed specifically around the delivery concept would be more capable than mine (which has been a series of somewhat haphazard experimental incremental changes).
Voltron said:
One advantage is actually being able to park it while unloading. For a normal delivery van that has to keep finding the next parking spot, that's a big deal in a crowded city.
Here in my area, I see all sorts of delivery vehicles that simply stop where they are to unload, even in "no stopping, standing, or parking" zones clearly marked as such, regardless of it's effect on traffic or the danger they place themselves and others in. Most respect where they are and operate safely...but more than enough that don't. The trucks that deliver to Castles'n'Coasters up here on Metro Parkway generally are some of the worst I've seen; the only ones consistently worse are Rent-a-Center trucks (though there are numerous individuals in every delivery company that are pretty bad).
None said:
I see the need for possible dual disc front brake for the USPS delivery e-trike.
With the load on the rear, the rear wheels will be able to do pretty heavy braking, possibly even better than the front. (depends on if they have a suspension system or not, and how it operates in load transfer)