Roundabouts may have lanes but don't expect anyone to use them properly. Always give way to drivers already on the roundabout, whichever lane they are in and don't expect the lanes to merge into exits as they do in the UK. You have to actively switch lanes in Portugal otherwise you'll just end up driving in circles!

Portugal has a very specific and strictly enforced roundabout law (Article 14-A of the Highway Code) that often confuses foreign drivers. The fundamental rule is that you must not use the outer (right) lane unless you are taking the very next exit. If you are taking any subsequent exit, you must enter the roundabout into the inner lane(s). You should only move into the outer lane once you have passed the exit immediately preceding the one you intend to take. Signaling is also critical: you should use your left indicator while circulating the inner lanes and switch to your right indicator only after passing the exit before yours to signal your departure. Violating this lane discipline can result in immediate fines ranging from €60 to €300. This system is designed to prevent "cutting off" other drivers and to maintain a high flow of traffic, making it essential for anyone renting a car in the Algarve or Lisbon to understand these lane requirements before hitting the road.