You have just acquired a Carrera GO Challenge circuit whose characteristic is to have only one lane for one car. Do you already have classic Carrera GO circuits with two lanes? So why not take advantage of both by combining them?
The trick is to use a crossing rail (letter H) that you ideally position just before the lap counter. After 1 lap on one lane, the car will change sides of the track to do another lap, then on the next lap return to the initial side of the track and cross the lap counter and the start/finish line. Thus a circuit of theoretically 5 meters for 2 cars will allow you to have a circuit of 10 meters.
Below is a simple oval that will allow you to understand the principle. But you can make a large circuit with multiple turns.
