Two regional railroads run through Norwich today. The railroads are now solely used to transport cargo. The black outline shows the boundaries of Norwich. The New England Central tracks, shown as a red line, travel along the west side of the Thames River from New London through Norwich to Canada. The trains that run on these tracks are operated today by the New England Central Railroad which is a subsidiary of Genesee & Wyoming.

The Providence and Worcester tracks, shown as blue lines, run south from Norwich along the east side of the Thames River through New London on to Providence. The P&W track also runs north from Norwich to Plainfield. At Plainfield the tracks split, and continue on to either Worcester or Willimantic. The trains that run on these tracks are operated by Providence & Worcester Railroad which is a subsidiary of Genesee & Wyoming.

Over the years, these railroads have been known by several different names because they have been owned and operated by many different railroad companies.