Thanks Anders. I keep trying to think of inexpensive add-ons I can make. Last night I printed out a bunch of billboards to put along some of the straight sections. I'm not sure if I like all of them after I got them installed. I'd thought about putting them on the curves to act as a taller guardrail but wasn't sure the cars wouldn't tear right through if at full speed.
I'll probably move some of them around if I can figure out a better placement.