Visibility and Road Hazards: Keys for the Exam

As a future driver, you must know that safety starts with seeing and being seen, and continues by knowing how to anticipate environmental hazards. In this article, we break down two fundamental topics for your theory: transparent elements and mirrors, and driving facing specific dangers like curves and tunnels.

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1. Visibility and Transparent Elements

To drive safely, the vehicle must be designed to offer a sufficient field of vision to all sides.

The Windshield and Windows

The windshield is the front glass and its function is to protect us and allow vision.

• Safety: Must be made of laminated glass; if it breaks, it does not shatter into sharp pieces.
• Maintenance: It is vital to keep it clean. Never operate the wiper with dry glass (you would scratch it) nor if the wiper blades are damaged.
• Breakage: If it breaks while moving (due to gravel), reduce speed and increase safety distance.

Cleaning Devices

• Windshield Washer: Sprays water with detergent. You must check that the reservoir is not empty.
• Heated Rear Window: Located on the rear glass, serves to eliminate ice and mist via electric filaments.
• Sun Visors: Protect from solar glare. Can be folded laterally.

Mirrors

They are the "eyes" at the back. Without them, driving would be impossible due to lack of information.

Classification and Obligation (Permit B)

Cars must mandatorily carry certain mirrors. If the interior mirror offers no vision (e.g., due to load or curtains), the right exterior one becomes mandatory.

Mirror Type	Location	Is it mandatory?	Condition
Left Exterior	Driver's side	YES	Always.
Interior (Central)	Inside the cabin	YES	Unless it does not allow seeing 60m behind and 20m wide.
Right Exterior	Passenger's side	NO (Optional)	Becomes mandatory if the interior one does not fulfill its function.

How to adjust mirrors

Regulation must be done with the vehicle immobilized and on flat ground.

• Interior Mirror: Oriented with the right hand until seeing the full rear window.
• Exterior Mirrors: You must see the roadway and only a minimal part of the bodywork of your vehicle (the side) to have a reference.
• Blind Spot: It is the zone not visible by mirrors. Even if mirrors are well adjusted, a blind spot may exist; sometimes it is necessary to turn the head slightly or use special curvature exterior mirrors to mitigate it.

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2. Specific Road Hazards

The road presents specific challenges requiring specific driving techniques.

Curves

They are sections where centrifugal force pushes the vehicle outwards.

• Technique: You must brake before entering the curve. Once inside, accelerate gently so the wheels grip better.
• Signaling: Signals P-13 and P-14 warn of danger. Directional panels (blue and white arrows) indicate danger level: the more panels, the tighter the curve.
• Prohibitions: In curves of reduced visibility, overtaking, stopping, parking, and U-turns are prohibited.

Tunnels and Underpasses

Are high-risk sections. It is mandatory to turn on lights (at least position and low beam).

Safety Distance in Tunnels

Given that an accident here is fatal ("oven" effect in case of fire), distances necessarily increase when not intending to overtake:

Vehicle Type	Minimum Distance (Meters)	Time Interval
Cars (up to 3,500 kg)	100 meters	4 seconds
Over 3,500 kg	150 meters	6 seconds

Emergencies in Tunnels

• By Breakdown: Turn off engine, put on hazard/position lights, place triangles/V-16 signal, and ask for help from an SOS post or mobile.
• By Fire: Approach the vehicle to the right, turn off engine, leave keys in and doors open (unlocked), and head to the emergency exit in the opposite direction to the fire (smoke rises and goes upwards).

Narrowings

When the road is so narrow that two vehicles cannot pass at once, the following priority order applies:

1. Signals: What priority signals (R-5 or R-6) or traffic lights/agents say.
2. Entry: If no signals, the one who entered first passes first.
3. Vehicle Type: If they entered together or there is doubt, the vehicle with more maneuvering difficulty has priority in this order:
   • 1. Special vehicles exceeding masses/dimensions.
   • 2. Vehicle combinations (trailers).
   • 3. Animal traction.
   • 4. Cars with trailer (up to 750kg) and motorhomes.
   • 5. Buses.
   • 6. Trucks.
   • 7. Cars and mixed vehicles.
4. Distance: If same type, the one having to reverse further passes.
5. Gradient: If same type and distance, the one with the wider or easier road passes.

Note on Gradients: On sections with steep gradients (slope > 7%), the vehicle going up has preference, unless it can pull over into a lay-by.

Other Important Hazards

• Gravel (Signal P-28): Increase safety distance to avoid windshield breakage and skids.
• Animals: Prioritized on duly signaled glens (word "CAÑADA" under signal P-23).
• Works: Signaling has a yellow background. Meaning is the same as normal signals, but they oblige equally. Workers and machinery have priority.
• Priority Vehicles: Ambulances, firefighters, or police in emergency service (lights and sirens). You must facilitate passage by pulling over to the right or stopping if necessary, but never braking abruptly.