Taxiway Junctions
Capot has a point - those widths mentioned in previous posts are for straight sections of taxiways. Once you get to any changes in direction/junctions the width has to increase to allow a defined clearance from the outside of the aircraft wheels. This clearance depends on the taxiway code.
There are a number of computer programs that do this for you by "driving" the aircraft around a plan of the pavements and tracking the wheel paths.