The Sky Road represents an 'alternate future' to the other books, as its events diverge sharply from those in the other books after 2059, due to a choice made differently by one of the protagonists.
... there are 17,006 people, 5,316 households, and 4,454 families residing in the town. The population density is 943.4/km² (2,444.3/mi²). There are 5,418 housing ...