New this year
This year's biggest change focuses on track maps of the long-gone Manhattan/Bronx IRT elevated network. All the lines are here: Second, Third, Sixth, and Ninth Avenue, including the sections in the Bronx, the Willis Ave. terminal and interconnection, and where the els connected to the subway system. Archival photos and the 1924 aerial map of the city aided in research for this section, which covers the els until their discontinuation.
Also included in the 2023 Edition are 1930-era track plans for the IND Second System, including the Second Avenue Subway as envisaged from that era, and connections from the lines in lower Manhattan to north Brooklyn.
Of course, all the latest changes have been incorporated, including the newly-reconfigured 42nd St. Shuttle that reopened in Sept. 2021. A few more signals were added this year, and plenty of new links in the PDF edition. Here's a sample of the old IRT elevated section: