The Kaldidalsvegur (officially known as Route 550) is a highland track in Iceland, with a length of 40 km with no unbridged river crossings. Four-wheel-drive vehicle is not legally required to traverse it, however many car rental companies forbid the use of their two-wheel-drive vehicles on this interior route.jalvegur. |. Kjalvegur (officially known as Route F35) is a highland road in Iceland, with a length of 168 km (104 mi), crossing Kjoelur, kjÃ¶lur a plateau in the highlands Of, iceland at an elevation of aboutâ600 700, metres from north to. south