An operator of a relevant service that is a general route service or a school service must provide the service in accordance with the operator's advertised schedules unless--
(a) the operator is prevented from doing so by an unforeseeable circumstance; or
Examples of an unforeseeable circumstance--
an incident
an accident, whether or not involving the vehicle providing the public passenger service
flooding or storm damage
Example of a foreseeable circumstance--
traffic volume
(b) the schedules, and services under the schedules, are not realistically achievable.