"These capacity constraints mean that you should allow plenty of time to reach your destination."
Hewitt is asking passengers to try to avoid the peak times of 7am – 9am and 2.30pm – 6pm on weekdays.
"If the bus has reached its allowed capacity, it will not be able to pick up additional passengers.
"We will do our best to limit the impact of this and we ask that caregivers and parents wait with children at bus stops, as they could be left behind."
Horizons is also asking that children use dedicated school-only services, if it's an option, rather than public services.
"Horizons is working with our operators to provide backup services where possible but the number of available buses and drivers is limited."
Hewitt also asks passengers to travel safely by physical distancing from others who are not in their respective bubbles.
"All passengers are responsible for following the two-metre physical distancing rules at bus stops and stations, as well as sitting at least one seat away from others not in their bubble.
"There will be clear signage on board and at stops to guide passengers.
"We really appreciate everyone's patience and kindness as we work within the limitations in place to keep everyone safe."
Hewitt also urges passengers to fill out contact tracing forms when using the bus.
"It is really important that each time a passenger uses the bus, their trip details and contact information are recorded.
"This is so we can provide this information to the Ministry of Health, if it is required."
Passengers are asked to call Horizons on 0508 800 800, or fill in the contact tracing form at https://horizons-covid-register.azurewebsites.net/contact