Some road rule changes come into effect on Saturday, October 1.

These are a pre-cursor to the major road rule change due to come into effect on March 25 next year when the give-way rule will change.

Several of the road rule changes coming into effect on Saturday relate to safety around school buses.

The Saturday, October 1 rule changes:

• Riders of motorcycles, mopeds and bikes, who are already allowed to use bus lanes (unless excluded by signage), will now also be able to proceed on a white ‘B' (bus) signal. This is designed to prevent riders blocking the way of waiting buses and will improve traffic flow.

• There is an existing requirement for drivers to reduce their speed to 20km/h when passing a stationary school bus, displaying a school bus sign that is stopped to pick up or drop off school children. From tomorrow, drivers passing a stationary school bus displaying an optional ‘school bus' sign with flashing lights, will need to reduce their speed to 20km/h. The bus driver will also be required to only operate the flashing lights for up to 20 seconds before and after the school bus has stopped. This will help to warn motorists that they need to take care and slow down as they are approaching an area where children are likely to be crossing the road.

• Drivers approaching a pedestrian crossing controlled by a school patrol will only be required to stop when the school patrol sign is extended. Patrols are trained to ensure children are only permitted to cross when the school patrol sign is extended so it's considered confusing and potentially dangerous for children to require drivers to stop when children are waiting behind the patrol sign but it has not been extended.

• Currently, a bus that is travelling on a school trip is required to display a school bus sign and is not able to exceed 80km/h. From tomorrow, buses travelling on school trips, where all passengers are seated, will not have to display a ‘school bus' sign and will be permitted to travel at 90km/h, in line with other buses on the road. This will improve traffic flow and also means that a wider range of buses and coaches will be available for hire.

• From Saturday, there must be a date of issue and an expiry date on medical certificates issued by medical practitioners exempting people from the requirements to use seat belts or child restraints. Currently there's no requirement to give a time limit on the medical certificate.