Rarotonga is made up districts containing several villages located mainly around the coastal fringe of the island. Avarua is the main village on the northern side of the island and has most of the population and services. People tend to refer to it as the town. Muri on the eastern side is probably the main tourist centre, with apartments and the Pacific Resort scattered around the lagoon. Aroa is on the western side is a protected lagoon and beach, and home to the Rarotongan. The airport situated in Nikao, is close to Avarua, about 2km anti-clockwise.
Rarotonga's main island is encircled by a 32km two-lane one each way bitumen road that is in good condition. There is also an inner road that is paved, but narrow, and doesn't quite go around the entire island due to property owners.
Expect a remarkable number of chickens to cross the road. It is hard to understand why they do this, but they do. Dogs, walkers, children, and coconuts provide other obstacles on the roads that keep driving interesting. The speed limit is 50km/h, with 30km/h in some towns. Allowing 30 minutes should really get you to the fartherest point on the island, provided you start off in the right direction.
The main road is called Ara Tapu. The inner road, Ara Metua, links side roads between the inner and outer roads and have more recently been given names. Addresses with just the village name in the address can be assumed to be on the main road, or not far from it. The local free maps available at the airport and tourist information are quite detailed, and list the villages, and most places of visitor interest.
If you head off on any of the unsealed roads that start off heading inland, expect them to quickly peter out to narrow unsealed roads, with stream crossings often more suited to quad bikes.
By bus
Buses circle the island clockwise and anti-clockwise every hour. Clockwise buses leave town on the hour, and anti-clockwise at 25 minutes past the hour, and take around 55 minutes for the trip. The locals all own scooters, so it is usually visitors using the bus service. The anti-clockwise buses break for lunch, and don't run Saturday afternoons, Sundays, early mornings or in the evenings. The clockwise buses do not run on Sunday evenings either. The sign on the front of the bus states its direction. If you're going to use it regularly, you can buy a day pass or a book of 10 tickets.
The bus has designated stops on the map, and there are a few bus shelters around to wait in. However the bus will pick up and drop off almost anywhere on the round island route, although the drivers prefer spots where they can pull off the road to let traffic pass. Single trips are $4, return trips are $7, a day pass is $16. All-day family passes cost $26, for two adults and an unlimited amount of children in the one family children are 15 and under. A pass for 10 one-way trips is $25.
Some buses have buttons to request a stop, but these are just for show. Pressing them will probably see you doing another lap of the island. Simply stand up and tell the driver when you want to get off.
By bike
Bicycles are a very practical way of getting around. Road speeds are slow, and taking the inner road is also an option for cyclists. It is illegal for bicycles and scooters to travel two abreast, and you must ride single file at the left of the lane.
Bicycle hire is available widely, most rental places and resorts have them. Don't expect them to be very high in quality.
On foot
The villages tend to be around 15-20 minutes walk from each other. Most places on the island are within walking distance to a beach, an ATM or small convenience store. There aren't many footpaths outside of Avarua & Arorangi, but traffic is slow and walking on the main road isn't a problem. Walking along the beach between villages is usually possible, especially at low tide.