All the major brands such has Scalextric, Carrera and Ninco have in recent years introduced Digital racing to their track systems. These brands still offer their track systems in both standard analogue and Digital.
A simple 2 lane analogue track circuit would only allow up to 2 cars to be raced by two operators (drivers) using the hand controllers wired to each lane. The cars are restricted to only one of the lanes.
Digital adds a new dimension to slot racing as it allows you to race multiple cars on any lane with the ability to switch lanes and overtake with the press of a button on your hand controller. Scalextric Digital uses the exact same track pieces as the standard analogue system but with additional items such as lane changers, powerbase and controllers. For the cars to work on the Digital system they need to be fitted with the appropriate Digital chips.