The Story of The Car Part 10: The Doors and Glass

The Doors.

Provide for the entry and exit and security of your car. Some vehicles can be set up so the doors lock once the vehicle has started moving.

Their shape and method of opening are part of the overall styling of the car and they are part of the passive safety of the vehicle. They do this by being part of the structure of your car.

They have a number of features which will include:

  • Load carrying pockets
  • Air bags
  • Arm rests
  • Handel’s for opening and closing 
  • Windows and their openers

They are also fitted with door brakes called stays. These are to smooth the shutting of the door particularly when the camber adds to the shutting force.

Care must be taken with the opening of doors as they can be hit by other road users. This can also include pedestrians on the pavement. You are obliged to ensure you open your doors safely. This applies to any door on your vehicle whether opened from the inside or out.

There are a number of types of door openings.

Conventional Doors

The door itself is hinged on the leading edge. This means if driven off the door will tend to close. When a saloon car only has 2 doors they will be bigger than a saloon car with 4 doors. The reason for this is the opening needs to be bigger to allow access to the rear of the vehicle.


Coach doors

These open from the trailing edge and are sometimes known as suicide doors. The reason for this is that they open if the vehicle is moving the airflow will force the door open. This creates a hazard for the oncoming vehicle and an unsecured occupant may find themselves in the road.

They are fitted to vehicles where the driver is opening the door for the passenger. You will tend to find them on taxis or chauffeur driven cars.

Sliding Doors

Used on larger vehicles such as vans or people carriers. A conventional door on a large vehicle would require a bigger space into which to open. So are space saving.

Other Doors

These tend to be used on concept vehicles rather than mainstream ones. Gull wing, canopy, butterfly and scissor doors among others. Because all these open upward if the vehicle has rolled it makes getting out very difficult. Also when parked there must be sufficient clearance above for the doors to open.

The Glass.

The glass serves a number of purposes to further the safety and comfort of the occupants. The most obvious is the taking and giving of information.

They give information by allowing the driver to use curtsy signals to other road users. But also by allowing other road users to observe the driver and make deductions about the driver’s intentions.

Over a period of time the windows of the ordinary passenger vehicle have become bigger to allow this taking and giving of information. Because of the importance of this your windows should be kept clean. This will help to prevent glare.

The window is part of the structure of your car. Without the glass it would be almost impossible to drive your vehicle at speed. The process of driving fast would become very uncomfortable due to dust, insects and the effect of the wind.

Along with the pillars and roof the glass provides protection to the occupants should the vehicle end up on the roof. The overall size and shape of the glass is an important aspect of the styling of a vehicle. 


Over a period of time the glass has moved from ordinary to toughened to safety laminate. This is to protect the people inside from harm.

If a stone was to be spun from the back wheel of the car in front onto your car windscreen. Its speed of impact will be that of your vehicle plus that of the stone. On a modern car the windscreen will stay intact in all but the worst impacts.

There is often a dot matrix around the area behind the rear view mirror. This is to soften the light when you look up to check your mirrors. The dot matrix will also extend round the edges of the windscreen to soften light which might otherwise be glare.


Side Windows and Rear Windscreen

Your side and rear windscreens are made of toughened glass in order to shatter. This property will be very important if people are trapped and the doors do not open. 

As with the front windscreen the rear one may also have a dot matrix pattern round the edges for the same purpose.


Tinted Glass.

Tints are used for many reasons. Styling, privacy and heat reduction being the main ones. In sunny countries tinting will protect the interior from UV damage.

The main problem with tinted glass is hiding information. When you are driving looking in and through other cars can be very useful.

In normal driving when you are looking out of your car tinting can reduce the contrast. In low light conditions it is the equivalent of putting on sunglasses. 

Outside your car by making it harder for people to see in. It is useful to know if a driver is being distracted or paying attention. When emerging from a junction with vehicles parked close to the mouth of that junction, we try to look through those vehicles.

Applied tints are sometimes sold on the fact it is difficult for a car thief to break the window to which the tint has been applied. This would also make it difficult for the emergency services to break the window to affect a rescue.

An applied tint could also invalidate your vehicles insurance as this could be viewed as a modification. You would need to check with your insurance company first, as after an accident the assessor will not be doing any favours.

As a tint reduces the amount of light internally, older drivers who need more light should be especially careful.

Syllabus For Learning To Drive – Cockpit Checks

© Liam Greaney