Driving in Hawaii is relatively straightforward as roads are well signed and in good condition, particularly on the island of Oahu. Home to the tourist mecca of Honolulu, Oahu's roads are the busiest and as such you'll find several freeways here as well as the most developed roads in Hawaii. Just like in mainland America, Hawaiians drive on the right hand side of the road and speed limits are expressed in miles per hour.
Driving in Hawaii can be done by tourists as long as you have a valid International driver's license or a foreign driver's license written in English. Cars and motorbikes can be hired from a number of reputable rental agencies for around US$28-$35 a day and are usually between 5 and 10 years old. Extended periods of rental also generally attract a discount so don't be afraid to rent for the entire time of your holiday.
Petrol does tend to be a bit more expensive, however given the majority of your Hawaii driving will be done over short distances it shouldn't impact you too much. Incidentally, car hire is in rather high demand in Hawaii so if you're thinking of renting a car during your holiday you should make arrangements well in advance. It's also important that you are familiar with all the terms and conditions of your car hire.
As a guest in Hawaii, you should observe all the road rules and local customs and drive with caution and courtesy. For example, the Hawaiians are a laid back people and as such, are also quite calm on the roads. Honking your horn is considered exceptionally rude by the local people, unless it is absolutely necessary for safety's sake. Hawaii driving can be an incredibly rewarding experience thanks to the breathtaking landscapes and is especially so when you drive with care and consider all the other road users around you.