Lighting and Optical Signals — DGT theory test questions

Lighting and Optical Signals is one of the topics tested on the official Spanish DGT theory exam. Work through the questions below in English — each one shows the correct answer and a clear explanation of the rule behind it — then take a full topic test to check you are ready.

35 questions

• What are the three main functions of a vehicle's lighting system?
• When lighting is mandatory and the vehicle is moving, which lights must be switched on as a minimum?
• During which period of the day is the use of lighting mandatory?
• When is lighting considered insufficient for driving?
• Is it mandatory to switch on the lighting when passing through a tunnel?
• Motorcycles must travel with their lighting switched on:
• Should lighting be used when driving on a reversible lane or a lane in the opposite of its usual direction?
• What do a vehicle's position lights indicate?
• What colour are the position lights at the rear of the vehicle?
• How many front and rear position lights must vehicles other than motorcycles carry as a minimum?
• What is the purpose of parking lights?
• What feature distinguishes reflectors (catadioptrics) from position lights?
• When is the dipped beam (low beam) used?
• Where is the use of main beam (high beam) permitted?
• You are driving at night on an unlit road with main beam on and a vehicle approaches from the opposite direction. What should you do?
• If a vehicle travelling ahead of you in the same direction is close, may you use the main beam?
• When is the use of the rear fog light mandatory?
• The front fog light is:
• After driving through a stretch of dense fog with the rear fog light on, visibility improves. What should you do?
• What colour are the direction indicators (turn signals)?
• What are direction indicators used for?
• In which of these situations must the hazard warning lights be used?
• What characterises the hazard warning lights compared with normal indicators?
• What do the brake lights (stop lights) indicate?
• When does the reversing light come on?
• What is the function of the number plate light?
• What are daytime running lights (DRL)?
• What advantage do adaptive (directional) headlights offer?
• You are carrying a heavy load in the rear of the vehicle. How does this affect the headlights?
• Why is it important to keep the headlights clean and correctly adjusted?
• In which of these situations is the use of the horn (acoustic signal) justified outside built-up areas?
• As a general rule, is the use of acoustic signals (horn) permitted within built-up areas?
• A driver uses a brief flash of the headlights during the day. What is its usual purpose?
• In the event of a breakdown, with which light signal can you warn other drivers, together with the warning triangle or V-16 light?
• Summarising the lighting rules, the three key ideas to remember are: