I have been so focused on 18-wheelers lately that it did not occur to me I might want something other than a tractor-trailer. This just "sort of happened" late yesterday afternoon, when I noticed I had a spare truck-length chassis on the back of one shelf, and I quickly scrounged up the other parts to make it. It has turned out to be a nice little refrigerated delivery truck that can cruise through my downtown, or, when I finish the country road, take to the highway with the big rigs.
The chassis (photo below) is a spare one I made a year ago wqhile making my two "Streets city buses - it is from the UPS-like "Streets van with the front axle unmodified, but a honking big can motor and flywheel and 3:1 reduction gearing. The very detailed cab is from a Corgi tractor - Freightliner I think, while the box is the rear half of a scratch build trailer I built for one of my earlier tractor-trailers, now butcheedr for parts for the third-gen trucks. A good feature is that, since it is an identical chassis to my two city buses, it cruises at the same speed at any voltage - hence I can put this truck and one bus out on my downtown 'Streets loop and they take more than twenty minutes before one catches the other and I have to reset them. A disadvantage is that as built, the vehicle is front wheel drive while the weight (motor) is over the rear axle: this may be challenged up the 8% grades my country road will have: power it has, traction, not so much. Note this is a refrigerated van - that was unplanned. I had to add weight over the front axle and to do so, inserted a 2 x 1 x 1/2 inch magnet into the front of the box over the cab (I didn't need the magnetic force, just a last minute boost in weight over the front that I could fit to the truck and make look like something. Most of the magnet is inside the box but this much has to protrude, so it is a chiller.
Here it is cruising through downtown. It will go much slower but this is the speed I will probably run it at.
And it will haul buns - here it is at about 8/10ths top speed.