Shikoku's Highway Network
Like the rest of Japan, Shikoku has an extensive tolled highway network. It is not 100% complete as yet as construction continues to fill in the gaps, however it does currently connect nearly all of the main cities.
These highways are not free but enable you to move from point to point much more quickly. Often the free coastal roads are a lot more scenic, but they are much slower and can often get congested as well.
Nominally the speed limit is 80 kilometres an hour, however this does not seem to be enforced, and hence most cars seemed to be doing over 100 km/h.
Having a rental car last visit, we saw quite a bit of Shikoku thanks to these roads.
3 Day Shikoku Railpass
JR Shikoku doesn't advertise this for some reason on its English language website, perhaps assuming that most visitors from overseas will already have the JR railpass to cover the whole country, or will not want to do extensive train travel in Shikoku.
Unlike the JR pass, there are no residency restrictions, meaning that those of us who live in Japan can make use of this pass.
3 days unlimited use of JR Shikoku's network for 15,700 yen. This includes all express services. It is also possible to use some JR Shikoku buses.
Can be purchased at any JR Shikoku ticket office.
Road and rail routes
Although Shikoku is an island, there are three separate series of bridges onto the island, one of which is shared with the railroad as well.
The first is the Shimanami Kaido from Hiroshima prefecture, the second is the Seto-Ohashi road/rail bridge from Okayama prefecture, and the third one goes through Awaji Island to Kobe.
From Okayama station on the mainland, there are direct trains to Matsuyama, Kochi and Takamatsu.