Well, not exactly a new rule, but more like a bit more of information for the game master. As the saying says, the best laid play-test adventures do not survive contact with experienced players.
It is only fortunate, because it showcases the weaker points of your system. Those pesky players always seem to do the unexpected. So that’s how I figured out I needed a few rules to determine how much time characters could move in and around New Paris.
The system takes into account method of transportation — walking, elevated and underground train and coach –, area of New Paris and the use of the streetwise skill, along with a table of average travel times. No dice rolling, simply put, those who are “good at” Streetwise will move faster and those who are “bad at” streetwise will move slower.