The criminal law regulates the use of motor cars. It sets out a number of offences to provide protection for other road users. Some of these offences are discussed below.

Careless and inconsiderate driving

Careless driving

'Careless driving' is defined as driving a motor vehicle on a road or other public place without due care and attention. You can be charged with careless driving if (and only if) the way you drive falls below what is expected of a competent and careful driver.

In determining what is expected of a competent and careful driver, any circumstances that you were aware of, or could be expected to be aware of, will be taken into account.

Examples of careless driving include:

• Overtaking on the inside (also known as undertaking)
• Driving inappropriately close to another vehicle
• Inadvertent mistakes such as driving through a red light or emerging from a side road into the path of another vehicle
• Colliding with a stationary car
• Making a U-turn on a busy road
• Ignoring 'give-way' signs

The offence of careless driving is often accompanied by other offences, such as speeding.

If an incident (such as a collision) occurs and you claim that you weren't careless, but rather that your vehicle experienced a sudden mechanical defect, you must be able to support this claim with evidence from a reputable garage mechanic.

Inconsiderate driving

'Inconsiderate driving' is defined as driving a vehicle on a road or in a public place without reasonable consideration for other people. In order to prove that you're guilty of this offence, prosecutors must show that another driver was actually inconvenienced by your driving.

Examples of inconsiderate driving include:

• Driving too slowly or braking without good cause
• Flashing lights to force other drivers in front to give way
• Remaining in an overtaking lane for too long
• Driving with un-dipped headlights when there is oncoming traffic
• Driving through a puddle splashing pedestrians

It's possible for a supervisor of a learner driver to commit the offence if they fail to supervise the learner properly.

Causing death by careless or inconsiderate driving

You'll be charged with this offence if your careless or inconsiderate driving kills another person.

Dangerous driving

'Dangerous driving' is defined as driving a vehicle dangerously on a road or public place, risking injury to any person or serious damage to property. You can be charged with this offence if:

• The way you drive falls far below what would be expected of a competent and careful driver; and
• It would be obvious to a competent and careful driver that driving in that way would be dangerous; or
• It would be obvious to a competent and careful driver that driving the vehicle in its current state would be dangerous.

The use of the word 'far' in the definition of the offence makes this a more serious offence than careless driving.

Examples of dangerous driving include:

• Driving a vehicle knowing it has a dangerous defect
• Driving too fast for the prevailing road or traffic conditions
• Driving aggressively, e.g. making sudden lane changes, cutting into a line of vehicles or racing
• Driving with an unsecured load
• Using a hand-held mobile phone or other hand-held electronic equipment when the driver was avoidably and dangerously distracted by that use
• Driving when too tired

If prosecutors claim that a vehicle was in a dangerous condition, they must prove either that you actually knew about it or that it would have been obvious to a competent or careful driver.

Causing serious injury by dangerous driving

You'll be charged with this offence if you cause 'serious injury' to another person and your driving was dangerous within the meaning of the dangerous driving offence.

To be guilty of this offence, the injury caused by the dangerous driving must amount to 'grievous bodily harm' (GBH), i.e. really serious harm. The court will decide whether the injury was serious enough to amount to GBH.

The following would, among others, probably be seen as a serious injury amounting to GBH if the injury:

• Causes permanent disability, the loss of hearing or sight or visible disfigurement
• Results in considerable loss of blood requiring a blood transfusion or an extended period of treatment/incapacity
• Results in broken bones or displaced limbs

Causing death by dangerous driving

You'll be charged with this offence if you killed someone because your driving was dangerous within the meaning of the dangerous driving offence.

In order to convict a person of this offence, the prosecutor only has to prove that your driving was a cause of death. It isn't necessary to prove that it was the only or even substantial cause of death.

If you displayed hostile intent, you can be charged with manslaughter and even murder if there is evidence of deliberate driving in the direction of a pedestrian victim.

Driving or in charge whilst over the alcohol limit

You'll be charged with this offence if you've consumed so much alcohol that the concentration of it in your breath, blood or urine exceeds the legal limit and, while in that state, you:

• Drive or try to drive a vehicle on a road or other public place; or
• Are in charge of a motor vehicle on a road or other public place

It's possible for you to be 'in charge' of a vehicle even when you're not sitting in it. So, if you have 'control' of your car and you appear to be intending to drive away because you have the keys in your hand, it's possible for the police to claim that you're 'in charge' of the car.

It's a defence if you, charged with the latter offence above, can prove that there was no likelihood of you driving while your blood, breath or urine exceeded the alcohol concentration limits.

The limits are:

• 35 microgrammes of alcohol in 100 millilitres of breath
• 80 milligrammes of alcohol in 100 millilitres of blood
• 107 milligrammes of alcohol in 100 millilitres of urine

Driving or in charge while over the controlled drug specified limit

You'll be charged with this offence if you've taken a specified controlled drug and the concentration of it in your breath, blood or urine exceeds the specified limit for that drug and, while in that state:

• You drive or try to drive a vehicle on a road or other public place; or
• You're in charge of a motor vehicle on a road or other public place

It's a defence if you can prove that at the time of the offence:

• there was no likelihood of you driving the vehicle while the level of the specified drug in your blood or urine remained above the specified limit for that drug, and therefore you weren't in charge of the vehicle; or
• the particular drug was prescribed to you for medical or dental purposes, and:
• you took the drug according to your doctor's or dentist's instructions as well as any relevant directions given by the manufacturer; and
• your having the drug immediately before taking it wasn't unlawful.

Driving or in charge while under the influence of drink or drugs

You'll be charged with this offence if you're unfit to drive because of alcohol or drugs and, while in that state, you:

• Drive or attempt to drive a vehicle on a road or other public place; or
• Are in charge of a vehicle on a road or other public place

If you're accused of being in charge of a vehicle while under the influence of alcohol or drugs, it's a defence if you can prove that at the time of the offence there was no likelihood of you driving the vehicle while you were unfit to drive because of the alcohol or drugs, and therefore that you weren't in charge of the vehicle.

Preliminary testing

Testing at the roadside

If you're suspected of driving under the influence, you can be asked at the roadside to do a breath test, an impairment test or a drug test. A uniformed officer will test you if they have reasonable cause to suspect that you've been driving, attempting to drive or in charge of a motor vehicle on a road or other public place and:

• You have alcohol or a drug in your body or you're under the influence of a drug;
• You had alcohol or a drug in your body or you were unfit to drive because of a drug and you still have alcohol or a drug in your body or you're still under the influence of a drug;
• You've committed a traffic offence while the vehicle was in motion; or
• An accident occurs due to the presence of a motor vehicle on a road or other public place (in this case, the police officer doesn't necessarily have to be in uniform to request a roadside test).

The preliminary breath test

This test must be done at the roadside. However, if the last-mentioned circumstance above applies, the breath test can be done at a police station. The breath test is designed to show whether the proportion of alcohol in your breath or blood is likely to exceed the legal limit.

The preliminary impairment test

This test involves an approved police officer observing your physical state while you perform certain tasks. This test can happen either at the roadside or at a police station. During this test, the police officer is under a duty to follow a code of practice that specifies:

• The kind of task you must do
• How to observe your physical state
• How the test will be carried out
• What can be drawn from the observations

The preliminary drug test

With this test, the police will get a specimen of your saliva or sweat to test whether you have a drug in your body. This test may be done either at the roadside or at a police station.

Failing to cooperate

It's an offence if, without a reasonable excuse, you don't cooperate with a preliminary test. A police officer can arrest you if you don't cooperate.

If the police officer reasonably suspects, as a result of a preliminary breath test, that the amount of alcohol in your breath or blood is over the prescribed limit, they can arrest you without a warrant.

Subsequent procedure

In investigating whether you've committed a drink- or drug-related motoring offence, the police can ask you to give any of the following:

• Two specimens of breath (the one with the lower reading will be used)
• A specimen of blood
• A specimen of urine

If a specimen of blood or urine is needed, the police officer will decide which one will be taken. A blood specimen won't be taken if a medical practitioner (or a registered health care professional) believes that, for medical reasons, it can't or shouldn't be taken.

If you don't consent to giving a specimen

It's an offence to refuse to provide a specimen without a reasonable excuse and you could be prosecuted as a result.

If you don't consent to giving a specimen of blood, a police officer can still ask a medical practitioner to take it if:

• You're someone that the police officer is entitled (as set out above) to request a blood specimen from;
• You appear to have been involved in an accident that is, or is part of, the matter being investigated; or
• You appear, for medical reasons, to be incapable of giving consent

A blood specimen can't be taken from you in the above circumstances if you're a patient in hospital, unless the medical practitioner has been told and hasn't objected to taking blood. However, a medical practitioner can only object if the taking of the blood or any warning of prosecution (if you refuse to give a specimen) would harm you.

After being informed that it was taken, the blood specimen will be sent for laboratory tests.

It is an offence if you refuse, without reasonable cause, to give permission for the laboratory test to be conducted.

Detaining

You can be detained after giving your specimen if a police officer has reasonable grounds to believe that if you were to drive or try to drive you would be committing a drink and/or drug-related motoring offence.

Driving without insurance

You must be insured against the risk of causing death, personal injury to other road users and damage to property before you can drive a vehicle. It's an offence if you let or cause another person to drive the vehicle if that person isn't insured to use it.

If you're using a vehicle on a road, you can be asked by a police officer to produce evidence to show that you're insured to use it.

If you're charged with this offence, you wouldn't be found guilty if you can prove that:

• The vehicle didn't belong to you and wasn't being rented by or on loan to you
• The vehicle was being used in the course of your employment
• You didn't know and had no reason to believe that a valid insurance policy wasn't in force

Speeding

If you're caught by the police going over the speed limit, you can be issued a Fixed Penalty Notice or made to go to court.