You can't put it in analog mode, as that will send power to the other rail, and the system will go into safe mode. If you're going to do it in analog, you should have only one side connected.
Actually, now that I think about it, if you do a typical rally loop with the APB next to a loop connected to both lanes, you'll cause a short, because the left rail of one lane will connect to the right rail of the other lane. So, in any case, with the APB and other digital bases, You should only have one lane connected, or use lane changers or pit lane sections so that the base lanes are only connected to one direction of the loop.
If anyone has done this in practice, I'd like to see how things worked out.