Demand response transit
A transit mode operating in response to advance reservations or on-demand requests from passengers to schedule and dispatch vehicles to pick up the passengers and transport them to their destinations. Demand response is characterized by not operating on a fixed schedule(time to destination) – The travel time points scheduled for a fixed route transit service and provided to the traveler for their journey. More but rather within a given service time range.
Adapted from https://www.transit.dot.gov/ntd/national-transit-database-ntd-glossary