The only road that connects the Highlands with the coast is the one
between Nabire and Enaroltali. I have heard conflicting reports on
whether this is actually in useable condition, but the latest word was
that in good weather conditions jeeps can make it through in 3 days.
The road between Jayapura and Wamena has been on the planning board
for well over a decade now, but it seems that in recent years more of
it has been swallowed up by the jungle than has been been newly built.
Don't count on it till you hear that it has definitely been finished
and put into use.
Within the Highlands, there is an interesting
network of roads that fan out of Wamena to all directions, all of
which finish in a dead-end sooner (southwards) or later (westwards).
They are serviced by some of the most run-down and jam-packed
minibuses you will see anywhere, but can be useful for getting to
trailheads. In Wamena there are plenty of becaks that can not only
take you around town, but also to villages around the relatively flat
Grand Valley.