The first reported slot car track appeared in America in 1912, but it was not until the 1950s that such tracks started to become commercially popular with the launch of Scalextric. Since then, longer and more outrageous circuits have been constructed, most beyond the means of the everyday user. The only issue with longer slot car circuits is power. The standard power packs are only useful on short circuits. You could just buy more power packs, but this will use up a lot of plug sockets and lead to a lot of wiring.