Planning

When planing a driving trip, GoogleMap’s driving time display is popular and common.
As the alternative, please try using this searcher. Also much  other information.
Northern Road Navi(E,Cs,Co,K)

Must Have

Must-have Handbook for Driving in Hokkaido(E)
can be downloaded at the above website. A basic and practical handbook provided by a pdf file of 52 pages, full color, plenty of photo images, good descriptions and the list of the related multi-lingual websites links, in English.
The below lines are useful especially.

  Chapter1 Let’s drive in hokkaido
    1-2. Seasonal charms of Hokkaido
    1-3. Regional charms of Hokkaido
    1-4. Useful pieces of knowledge for comfortable driving
    1-5. Observe rules and local customs!
  Chapter2 Reservation of rental cars
    2-1. Basic information on rental car services
    2-2. How to use car navigation systems
  Chapter3 Traffic rules and quick tips
  Chapter4 What should you do in a situation like this?