Driving is on the right with overtaking on the left. Iceland has more than 8,000 miles of roads but less than 3,000 miles of them being paved. Therefore when you go into the interior of the country you should prepare yourself for a bumpy ride and plan which kind of vehicle you are going to rent accordingly. At certain times of year the roads in Iceland become impassable and you may want to avoid them completely, or rent a 4x4 in Iceland
Landmannalaugar is one of those places of natural beauty where having an off road vehicle is recommended, though these get snapped up quickly and should be rented well in advance. Always take advice from locals who know the roads and take particular care when crossing fords. Having a weather report is vital as conditions can deteriorate quickly and you should plan your petrol and rest stops into your trip. It is forbidden to drive off road and on certain marked tracks. You must always give right of way to domestic animals and always take care when passing horses. Pay attention to the signs in Iceland as paved roads often become gravel roads and you need to change your speed accordingly, especially when this happens on steep and windy roads where one wrong turn could send you off a cliff. High wind speeds are also responsible for many of the accidents in Iceland.
The opening hours of gas stations in Iceland vary but most are open 12 hours per day from 8am to 8pm with some closing at 10pm and even 11pm. If you have a credit card you can usually buy petrol 24 hours a day from the machines.