[steven]

Jeez... you know, I drive every day but I have no idea where to start on this.

Driving through Japanese cities can be a very stressful and confusing experience (driving through any city is like that for me though). Your car will most likely come with a navigation, but I doubt it will speak/read in anything but Japanese. To type in a location you at least have to know hiragana, but just knowing that would probably make it impossible. Inputing phone numbers is going to be your best bet for that.

In my experience MOST people drive faster than the posted limits. Some people go exactly that speed and some people might even go slower. On the toll roads, like Nyororin hinted at, anything does go. You will occasionally get stuck behind someone going like 60 or you might have someone behind you who wants to go 180 (which is uncommon, but they do exist). I'd say a good, but fast speed, to go on the toll roads would be around 100-120. It's kind of an unspoken rule that going past 120 has bigger consequences if you get caught. Another thing, entering big cities can be a dangerous affair. You will often hit a brick wall of traffic in that you might go from 120 to 0 VERY quickly.

Look out for hazard lights (or emergency lights or whatever you want to call them)... if you see a lot of cars in front of you doing that then it means you need to slow down because traffic has stopped up ahead. This is especially important to pay attention to in tunnels or around curves. A quick hazard light flash usually means "thanks for letting me in" or "I'm sorry" and stuff like that.

I'm not sure about the logistics of doing so, but see if you can't get an ETC card or something like that... that will allow you to not have to stop at toll road gates and will also provide discounts. For example, on the weekends you can go any distance (on a given road) for 1000 yen, which is fairly cheap. Otherwise you're looking at high costs... I've never done it, but I'd guess one way from Tokyo to Nagoya (maybe Nyororin knows about this) would cost about 4000-5000 yen. From Nagoya to Osaka maybe about the same. Some roads do cost more than others, and in big cities you have multiple options. Some roads you CAN'T use your ETC card... so it's a good idea to keep some change in the car just in case (which I'm sure you'll have plenty of while travelling).

As far as the reality of time/distance and what is written on google maps/navigation systems, I have found that it usually takes LONGER in BIG CITIES and LESS TIME in the COUNTRY SIDE. This has to do with traffic and traffic lights. I think my navigation system has some how figured out my average speed on toll roads so its estimations have improved recently. So if you decide to use your navigation depending on whether or not the person who drove the car before you was fast could change the time estimates it gives you.

My driving experience has led me to beleive that there will be a traffic jam MOST of the time at all hours of the day when entering a big city. I've driven at ungodly hours and still ran into that "wall of traffic" that I was talking about earlier. Sometimes it's not there, though... so you never know. Usually the "wall" lasts longer on weekends/holidays.

If I were you, I'd really study the rulebooks (if you can find any) as they might save you from making a mistake (which wouldn't be a mistake in your own country) that could cost you time and money.

This is very important:
There's NO drinking and driving in Japan. I'm sure you've read about it before, but this is serious. I can't imagine what would happen to you if you were to be caught. I'd imagine you'd be sent home and not allowed back to Japan or something to that degree. Plus you'd probably have to deal with the embassy and all kinds of fines and apologies and the whole nine yards. When I say "drinking and driving" I don't mean sippin' a beer while behind the wheel, I mean like having a beer for lunch and then going for the drive hours later in the afternoon. They are seriously super strict here about that. This is the ONE bad thing about driving while travelling in my opinion. If you want to have a drink you honestly can't.

And just for a little warning, Japanese rental cars are gross... they are "clean", but they seriously reek of cigarettes... like honestly. I'd imagine even someone who smokes feeling sick sitting in one of those cars. Even if you get a "non-smoking" car, it will still smell of cigarettes... just to a slightly lesser (mroe tolerable) degree. I can't imagine any harm would be done by doing so, so you might just want to make sure you get a "non-smoking" car... even IF you smoke. It might cost you a little bit more, but it could save you and whoever rides with you a huge headache.

"I think sometimes people aren't aware how advanced and easy the metro Japanese train systems are."

While I agree with the overall sentiment that using train would be a better thing to do, I have to admit that there are some things about it that aren't as good as driving. (although while traveling the good outweighs the bad).

1. Even though it's fairly simple and in English, it is STILL stressfull (less stressful than driving in a city, more stressful than driving outside of a city).

2. Carrying heavy luggage in a train/subway is a pain in the...kaboos. (but this can be fixed by using "kuroneko/black cat" or any similar mail service, which are very cheap)

3. They're expensive (even with a pass... a car is cheaper)

4. Sometimes a car is faster (for example Nagoya to where I live is about a 2 hour dive. Taking the train would cost I don't know how many times more and take about 3-4 hours).

5. You're generally stuck to wherever the rails take you (although the pass does include some busses and other public trans I think)

6. You can fall asleep and miss your stop

7. You can get separated from someone (although if you're responsible and careful this probably won't happen)

8. Train stations (in big cities) can be crowded and hot.

9. Sometimes you have to run through a train station to catch a train

But to be honest, MMM is pretty much on the money. While I've heard of some of these things i just listed being factors in peoples' travels, I'm sure they are in the minority. Most of the time it's smooth sailing. Pretty much everything is in English and the employees are very good at speaking English (even in the countryside they're generally pretty good... although I'm not sure if the guy who works the gate in my town can even speak Japanese... or is even living for that matter... I think he's not a people person, which is very uncommon for JR, which has great employees in my experience). If I were to list all of the dangers or downsides of driving in Japan while traveling from another country, I could go on for days!