I posted some pictures and a link to a Youtube video of an O-Gauge, wire-following REA 14-wheeler big rig I built a week or so ago. It is a superb truck, but geared for highway speeds to run on my (yet to be built) wire-guided country highway, and too big to really run well through my downtown area. Last week i decided to build a shorter, smaller "city tractor trailer truck" geared for city driving speeds to run on my Main Street loop. It proved to be difficult to build and took five days, during which I experimented and learned a good deal more about building tractor trailer trucks. As completed it looks a a bit ugly, but has to be this short in order to run well through the downtown streets' tight curves, etc. It runs well and at the right scale 22 mph I want for my downtown loop. Here it is:
This is a link to a video of it running one lap around downtown. There are a couple of bad moments for it, but those are issues I am fixing with the road and tunnel height, that affect other vehicles, too. Overall I like having this little ugly fella on the layout!!
https://www.youtube.com/watch?v=fb3JjURnCpg