Personal Rapid Transit (PRT)

The Advanced Transit Association (ATRA) has provided this definition of Personal Rapid Transit (PRT):

• Direct origin-to-destination service with no need to transfer or stop at intermediate stations.
• Small vehicles available for the exclusive use of an individual or small group traveling together by choice.
• Service available on demand by the user rather than on fixed schedules.
• Fully automated vehicles (no human drivers) which can be available for use 24 hours a day, 7 days a week.
• Vehicles captive to a guideway that is reserved for their exclusive use.
• Small (narrow and light) guideways are usually elevated but also can be at or near ground level or underground.
• Vehicles able to use all guideways and stations on a fully connected PRT network.

Group Rapid Transit (GRT)

Group Rapid Transit (GRT) has a similar definition but uses larger vehicles (typically up to about 25 passengers) and often incorporates intermediate stops. Modern PRT deployments often encourage ridesharing and the lines between PRT and GRT are becoming blurred. The term Automated Transit Networks (ATN) is a useful umbrella term incorporating both PRT and GRT. It is used interchangeably with PRT in this website.

The key technology distinction between ATN and other guideway systems is that the switching is in the vehicle. The rails (guideway) do not move. This is what enables very short headways (times between vehicles) and offline stations