ACCOMMODATIONS
Some people don't like to plan their trips - they prefer to just jump on the bike and head off in a new direction, on a road less (or never) traveled. If you're one of those people, you can probably skip this section... and most of the rest of this site. The problem is that routing mistakes made on a bicycle tend to take a lot of time and energy to correct. So unless you're the type of person who doesn't mind a lot of backtracking and sleeping under the stars, route planning will be an essential part of your bike trips.
The first thing to keep in mind is that route planning is an art, not a science. Common sense and experience will usually help you plan a decent route... but not always. That tiny coastal road on the map that would ordinarily be a cyclist's dream may turn out to be a horrible slog with no scenic beauty to compensate. Conversely, the normally awful major highway may actually not be so bad, and it may save you immense amounts of time in getting to someplace really nice to cycle.
But even if your plans need to be adjusted to match reality (and what plans don't?), it stands to reason that any research you do on your intended route will help you immensely on the road.
It follows, therefore, that whatever references you can bring along with you will help when, inevitably, you have to do some checking or impromptu rerouting. A good map is the most essential item; keeping the page for the area you're cycling through folded up in your pocket is a good idea for instant reference (placing it in a clear plastic bag will make less crinkles when you fold it and will also protect against rain and perspiration). Taking a guidebook will also give you more information on which to base route decisions, and will also enhance your enjoyment of places of interest along the way. The key factor is weight: you don't want to be hauling heavy guidebooks like Japan Inside Out along with you unless you're touring the entire country. Ripping out or photocopying sections of your guidebook will reduce the load considerably. If you plan to stay in youth hostels, carrying along pages from the hostel guide or the JYH website will give you those all-important phone numbers to call ahead and reserve a bed for the night. (The same goes for minshuku, ryokan and other traditional Japanese accommodations, though you'll have to read Japanese to take advantage of these references in most cases.)
Electronic toys can help here. Lately I’ve spent a bit of additional time before each major trip scanning lengthy sections from guidebooks into my trusty Macintosh computer which I carry on the road with me. This reduces the guidebook weight enormously.
In route planning, small roads are better than big roads - but this does not apply to road numbers. Highways with smaller numbers are invariably major highways: national Route 1 or 41 will be larger (and more heavily traveled) roads than, say, national Route 257. Smaller local roads are almost always less traveled and usually greener as well (but generally more mountainous). Look for places connected by major highways that also have other, less direct routes, and take those. The classic example is the coastal road between two destinations that are also connected by an inland bypass. In such situations, the coastal route is usually (but not always) a good option. Conversely, if the coastal road is the only route between two destinations, you can bet it will be clogged with cars and trucks.
Best of all are bikepaths (or "cycling roads" as they are called here). Luckily, more and more of these are being built - some along old railway lines that have been discontinued. The problem is finding them: many are local projects, and it seems that there is still no central resource for all of the bikepaths in Japan (though many of them can be found here: http://www.mlit.go.jp/road/road/bicycle/road/index.html).
This section has been divided into numerous subsections in three categories: Transport, Maps and Accommodations. Click on the links above to go to the section that interests you.
For other reference materials that you may find useful in route planning, see RESOURCES.
MAPS
TRANSPORT