Are you surprised that I'm going to tell you about how important it is to have a car in Japan? "But, Eric, Japan is a country of trains and amazingly awesome public transportation! You don't need a car!" Generally, public transportation is great in Yamato (mainland) Japan; however, Okinawa has little to no public transportation, depending on the area. There is one train system on the entire island, and it just covers Naha (the capital city).
A lot of travelers coming to Okinawa are baffled at the fact the #1 best way to get around Okinawa is by car. (Scooters are also awesome if you have a license and it's not raining) When we moved to Okinawa from the States, we were surprised that a car was highly recommended. This raised a whole bunch of questions for us: Do we need a special license? How much does gas cost? What are insurance costs like? What happens if we get into a crash?
Getting a driving license in japan is fairly difficult, involving at least 3 different written tests and one hard/easy to fail practical driving test. If you fail any of the tests, the process starts all over again and you could be out $2000-5000, from what I've heard. AAA offers an International Driving Permit good for one year costing about $15 (plus the cost of a passport-size photo $10-$15), which allows you to drive in Japan for a year starting after your entry. This is the license we used for our one-year stay.
Our JET predecessor offered her older Honda Life, a Japanese kei car. A kei car is a very small vehicle (by American standards) with four seats and what amounts to an engine slightly more powerful than an average motorcycle engine, 660cc max displacement. To compare, your average Toyota Corolla has a displacement of 2000cc +. Kei cars are taxed differently than their larger counterparts, and on the expressway kei-cars pay a cheaper toll; both factors make it cheaper to own a car overall if you decide to get one in Okinawa.
I don't know how Japanese car insurance companies make money. Most cars, when you purchase them, come with Japanese Compulsory Insurance (JCI), which is basic-level insurance for about $100. Voluntary Insurance is highly recommended and offered by most insurance companies. Our Voluntary Insurance cost about $160. So we paid a total of $260 for not just one year but for 5 years. I guess part of the reason the prices are so jaw-droppingly low is that there are fewer people driving, but still--that's insane.
Cars in Japan are inspected every 2-3 years, and they call this inspection Shaken. Shaken can be very expensive, and it includes the cost of JCI. Since our vehicle was inspected a year before we came, we didn't have to worry about it. According to Wikipedia, shaken can run as much as $600, which I'd gladly play because it includes JCI and the comparative cost of car ownership overall is cheaper in Japan.
Is this starting to sounds like a dream come true? Cheap kei cars and cheap insurance, right? Well, there's no way of getting around this fact: Japanese gasoline costs $6+ per gallon. As a family, we spend about $30-40 a week on gas. (Remember that we're driving a tiny golf cart-like car.) On the plus side, most of the gas stations or "Gasoline Stando" in Japanese are full-service, meaning we have almost never had to fill our own gas tank. They wash the windows, throw out your garbage, etc. Japanese gas attendants are probably the most energetic employees we've seen in Japan, even compared to those at the FamilyMart convenience store, who all shout, "IRRAASHAIMASEE!" (welcome) when you walk in. Gas station attendants never fail to wow us with their incredible level of customer service. Just this past weekend, one worker noticed our tires were low, and after making sure it was OK, filled all four of them on the spot. When everything is done and you've paid, they bow as you exit the station. Kelly and I will definitely miss the full-service gas stations.
So far, we're very thankful that we haven't gotten into any car accidents. Based on what we learned at JET orientation and from reading various books and manuals, this is one situation you want to avoid at all costs. There's really no concept of "fault" in accidents here, so both parties are penalized equally. You could be parked on the street and a drunkard slams in to the back of your vehicle and both of you are at fault. Drunk driving has harsh penalties in Japan a license can be suspended/revoked on a single drink. A fine of $5,000 to $10,000 can be charged depending on how drunk the driver was.
Japan has a point system similar to California's point system in which I have personal knowledge about. A few minor traffic incidents; speeding, running a red light, etc will net you a suspension. 15 points will net a suspension and drunk driving is 25-30 points which is revocation/removal of the license (They take it away).
Drivers in Japan drive slower than their US counterparts and speed limits are also much lower. The speed limit on the Okinawa Expressway is 80kph (roughly 50mph) on city streets it runs between 30-50kph (18-30mph) there are areas were people speed of course and others where drivers respect the speed limit. I grew up in California where 90 mph is cruising speed and drivers will change lanes erratically; cross 4 lanes of traffic in less than a second, fast lane means the fast lane. So Japan is a rather welcome change to the constant white knuckle driving of California and sometimes Chicago.
Driving in Japan can at first seems overwhelming, 'They drive on the wrong side of the road?' but isn't too different. I feel more comfortable driving in Japan than I do back home, and will miss almost everything about driving here. The incredibly harsh punishment on drunk driving, does make the roads safer. Small Children when they cross the road, will hold up their hands so they are visible to drivers who may not see them. So if you plan on visiting Okinawa or almost any other of the smaller islands around Japan Renting/Hiring a Car will make a visit all around easier.