I'm trying to get a general idea of railroad traffic along particular segments of track—whether it's abandoned, whether it gets one train a month, or 100 trains a day. Is there a source of such data? I've had no luck on the Department of Transportation's website, and no luck on Data.gov.
As a supplement of open data, the Federal Railroad Administration in the U.S. provides data on incidents, casualties, and a listing of the rail crossings. FRA also provides geospatial data on the location and maps of rail networks.
It could be possible to interpolate train traffic between two grade crossings as well. You could experiment with the FRA grade crossing data. The grade crossing file captures day and nighttime movement counts, as well as crossings where there is less than 1 train per day. The specification is available.
Weekly rail traffic summary: https://www.aar.org/newsandevents/Freight-Rail-Traffic/Pages/default.aspx
Rail time indicators (not free and structured): https://www.aar.org/newsandevents/Pages/Rail-Time-Indicators.aspx