The ones I was surprised at were St. Louis Metrolink and Pittsburgh PAT, which are clearly light rail. If “runs partly underground” is the criterion they’re using, then Newark City Subway and Hudson-Bergen LR should both be added. Else, there’s a bunch that need to go away
The existing monorail isn’t even really transit – it’s more of a tourist attraction. It goes from the space needle to a big mall downtown, and that’s it. There was an effort to build a monorail to serve the north-south corridor on the west side of the city, and there were four votes in support of it, then after financing troubles and with all the necessary property already acquired, it was killed in a fifth vote. Now it seems the gods of the single rail have cursed the city.