This is made up of C191, C192, C193 and C194 and a piece of straight track. The previous owner had the pits set up for fuel stops. The "points" were operated by model railway points motors which where controlled by an old (Amstrad) computer.
On further examination (eg. trying to find the part numbers) I discovered that the straight section in this picture with the bits sticking out to the side is actually a piece of SCX track (PT/3060). I probably got this straight muddled up with the straight that was actually used by the previous owner of this set. It has isolated sections with addition wires soldered to them. This will require futher investigation.