I remember a few years back when I was an unloader it usually took about one hour to unload a 52 footer 100% full by yourself... Maybe things have changed now... who knows...
The wild card in this discussion is the loading and unloading of the package car itself. This is a whole other can of worms. The unloading is all but the same it was 35 years ago when I first came to UPS and even the unload device is all but the same, at least in the concept. The device has some better engineering features, even includes an idea I came up with (no I got nothing for it and it was minor) but it's all still the same. Loading the car is still the same as well, we just use technology to de-skill the position.
Part of the problem of automating the load/unloading of the package car is the package car itself and how it is constructed along with the processes of delivery and pickup. To fully automate the loading and unloading of a package car seems to me at this time to be a whole other kettle of fish indeed.
But I've heard some intriguing ideas too!
If you load and/or unload package cars, I wouldn't be to worried at the moment.