Lead quad axle vs lead tri w/pup

Asphalt can be hauled and dumped in a pup.

It's done all the time.

The pup gets unhooked somewhere on the job site so the truck can dump.

 

Lots and lots of asphalt gets hauled on aluminum trailers too

 

Webonly use end dumps with asphalt on the smaller jobs, or doing the turnouts on the bigger ones, everything else it is hauled in bellys.

 

'A' Trains were probably developed as a more economical means of weight gain without too much added cost in equipment. 'A' trains track well in tight spaces; as long as you have drive through ability and you don't fold the dolly on the pup.
'A' trains are long, my rocky mt set is 89 feet. They most likely cannot be backed more than about 10 feet and it takes patience,skill and focus to drive in large metro areas (I'm in Seattle).
That being said, when my trucks in the shop and I'm pulling the company's single barrel 5 axle set-up, I'm more than happy to get back into the train.