As of January 2017 there are only fifteen fully driverless train systems in the United States, mostly in airports, each with at most a handful of miles of track.

Judge as of January 2017, counting US rail or guideway transit systems running in regular passenger service with no driver or attendant at the controls (GoA4 / unattended train operation, including airport people movers, monorails and automated guideway systems). The claim has three parts: (a) there were fifteen such systems; (b) most were at airports; (c) each had at most 'a handful' of miles of track (read as single-digit route-miles, no more than about 10). True: a credible inventory gives exactly fifteen, or a count that falls on fifteen under a reasonable definition of 'system'; more than half are airport systems; and none has more than about 10 route-miles. Mostly true: (b) and (c) hold and the count is 13–17, which reflects differences in how systems are defined and counted. Mixed: the count is roughly right but either 'mostly in airports' or 'at most a handful of miles' clearly fails, for example a fully driverless system well over 10 route-miles. Mostly false: the count is off by more than 2 but still in the same range (about 10–20), or both secondary parts fail. False: the count is badly off (under 10 or over 20), or most such systems were not airport systems and some were long lines.

Set before the research began.

1. E1 Monorail Global Scan May 2020 - Maryland Department of Transportation Maryland Department of Transportation (MDOT) · May 2020

   “While the global scan included approximately 90 monorail systems, this white paper presents information on a smaller subset of eight (8) monorail systems,”

2. E2 List of driverless train systems - Wikiwand Wikiwand (mirror of Wikipedia list)

   “These systems are capable of unattended train operation (UTO), although some operators may choose to staff trains anyway.”

3. E3 Monorail Global Scan Maryland Department of Transportation (MDOT) · May 2020

   “At the time of this study, 57 systems were operational around the world, eight of which are in the United States.”

4. E4 Monorail Global Scan Maryland Department of Transportation (MDOT) · May 2020

   “This paper does not include people mover type systems intended for tourist attractions.”

5. E5 Monorail Global Scan Maryland Department of Transportation (MDOT) · May 2020

   “They also have the same technological flexibility to operate driverless or via an in-car operator, similar to characteristics of light rail and metro systems (i.e. subway, elevated rail).”

6. E6 Las Vegas Monorail - Wikipedia Wikipedia

   “The Las Vegas Monorail is a 3.9-mile (6.3 km) automated monorail mass transit system located adjacent to the Las Vegas Strip in Clark County, Nevada, United States.”

7. E7 All Aboard Airport People Movers AviationPros · 23 August 2018

   “At last count, there are 51 airports with automated people mover systems around the world. Nearly half (24) of those are in North America.”

None of the evidence gives a count of fully driverless (GoA4) train systems in the United States as of January 2017. E7 says 24 airports in North America had automated people movers in 2018. That figure covers a wider region, comes from a later date, and does not count US systems as the criteria define them. E3 counts eight US monorails in 2020 but does not say which of them run without a driver. E6 describes a single non-airport system of 3.9 miles, which does not settle any of the claim's three parts.