Line 100 was created in 2003 following the redrawing of a number of bus routes in the concession by the barony and Connexxion, including the renumbering of a number of bus lines. During this process, line 100 was newly created specifically for day travellers arriving by car and parking at one of the park and rides, so that they had a fast alternative to travel to the Old City in addition to the other possible bus lines.