Road route map in English?

Is there a website in Japan that you can plan your driving routes with (Takayama to Matsumoto for example) in English?

I am not aware of such a website, but you are welcome to post questions here.

The drive from Matsumtoto to Takayama, for example, is very simple. You just follow National Route 158 all the way. In the middle, there is a toll tunnel (750 yen). The whole trip takes about 2 to 2.5 hours.

thanks Uji. We will be driving in several regions - there should be a website where you put in your location and destination and it plots the route. But is it in English??

http://maps.live.com/

This works.
but you won't get any calculation of toll charges.

Have you driven in Japan before ? Nearly all Japanese car rentals come with GPS navigation as standard equipment. Once you've used it you will not need maps.
Maps needed when PLANNING your trip. Most people use the Road Atlas Japan published by Shobunsha. It's a very good English atlas with place names in both English and Japanese and all the road tolls. I bought it online but my public library at home also carries it. l find it so much easier to plan with an English atlas.