The rules of the road in the UK include driving on the left-hand side of the road, obeying speed limits, using signals when turning or changing lanes, giving way to pedestrians at crosswalks, and wearing seat belts. It is illegal to use a mobile phone while driving, and the legal blood alcohol limit is 80mg of alcohol per 100ml of blood. Roundabouts are common in the UK, and drivers must give way to traffic already on the roundabout. Drivers must also carry a valid driving license, insurance, and registration documents at all times.