§ 509-k. Ill or fatigued operator. No driver shall operate a bus and a
motor carrier shall not permit a driver to operate a bus while the
driver's ability or alertness is so impaired, or so likely to become
impaired, through fatigue, illness or any other cause, as to make it
unsafe for such driver to begin or continue to operate the bus. At the
request of the driver or the motor carrier such illness, fatigue, or
other cause shall be certified by a qualified physician or nurse
practitioner. However, in a case of grave emergency where the hazard to
occupants of the bus or other users of the highway would be increased by
compliance with this section, the driver may continue to operate the bus
to the nearest place at which that hazard is removed.