Drink Driving is a very complex area of law with possible offences including:-

• Driving or attempting to drive while unfit to drive through drink or drugs 
• Being in charge of a mechanically propelled vehicle while unfit to drive through drink or drugs 

also;
• Driving or attempting to drive "on a road or other public place" after consuming so much alcohol that the proportion of it in the his breath, blood or urine exceeds the prescribed limit 
• Being in charge of a motor vehicle "on a road or other public place" after consuming alcohol so that the proportion of it in his breath, blood or urine exceeds the prescribed limit 
• Without reasonable excuse, failing to supply a specimen for a breath test 
• Without reasonable excuse, failing to supply specimens of breath or blood or urine for analysis 
• Without reasonable excuse, failing to allow a specimen of blood to be taken for a laboratory test 

Preliminary Breath Test [s.6 1988 Act]

Most (but not all) Drink Driving offences involve what is known as a "preliminary breath test" which is often administered at the roadside by a police officer using one of the approved breath test devices such as the Lion Alcolmeter or Draeger Alcotest.

The police are entitled to stop any motor vehicle for any reason [s.163(1) 1988 Act]. Once a vehicle is stopped if the police have "reasonable cause" to suspect that the driver is or has been driving with alcohol in his body or is attempting to do so or has committed a "moving traffic offence" a preliminary breath test may be administered even if the vehicle was initially stopped at random.

It is important to appreciate that a refusal to cooperate with a request to take a preliminary breath test may result in a conviction even if no "moving traffic offence" has actually been committed or even where the driver has consumed no alcohol. If the police "had reasonable cause to suspect" the commission of an offence or the consumption of alcohol they are normally entitled to insist that a preliminary breath test be taken. The police have similar powers to breath test any drivers who they have "reasonable cause to believe" may have been involved in an accident.

The police may also be entitled to demand a preliminary breath test from a motorist who is or was "in charge" of a vehicle. Accordingly the supervisor of a learner driver or the car owner who decides to "sleep it off" in the front passenger seat could in the appropriate circumstances be required to provide a breath test.

Failure to provide a specimen will usually lead to an arrest as will a positive result [s.6(5) 1988 Act].

Driving or in charge above the limit [s.5 1988 Act]

After arrest the suspect can expect to be taken to a police station where he will usually be required to provide 2 specimens of breath using one of the approved evidential breath testing machines such as the Lion Intoximeter EC/IR or Intoxilyzer 6000UK or the Camic Datamaster. Failure to do so without reasonable excuse is an offence.

If a driver claims he is medically incapable of providing the required specimens the police may arrange to obtain medical advice although they are not obliged to do so. Usually the driver will then be asked for a blood or urine sample and failure to cooperate without reasonable excuse may be an offence.

The "prescribed limit" is defined by s.11(2) 1988 Act as 35µg [microgram's] of alcohol in 100ml of breath, 80mg of alcohol in 100ml of blood or 107ml of alcohol in 100ml of urine.
If the lower of the 2 breath specimens is no more than 50µg the suspect may ask for a blood or urine sample to be taken. It is for the police to decide which type of sample will be taken once a request is made.

In theory the police can call expert evidence to show that at the time the suspect was driving his alcohol level was greater than the amount revealed by the breath test or sample results ["back calculation"].

Driving or in charge whilst unfit [s.4 1988 Act]

Usually anyone arrested for this offence will have been asked to provide a preliminary breath test e.g. at the roadside, and will be required to provide 2 specimens of breath etc. at the police station. Accordingly anyone charged with an offence under s.4 will usually also be charged with an offence under s.5 [if a specimen is provided indicating an alcohol level over the prescribed limit] or s.7 [if a specimen is refused]. When the case is heard by the court it is common for either the s.4 or s.5 charge to be withdrawn if both offences are alleged.
S.4 is often used if there is evidence of impairment because of drugs [legal or illegal] or a combination of drugs and alcohol. Impairment can be established by evidence of poor or erratic driving, an unexplained and inexplicable accident or pre driving alcohol or drug consumption.

Penalties

The following represent the maximum penalties but please remember the situation may be different for new drivers and those at risk of disqualification for "Totting Up". A prompt "guilty" plea may attract a discount on the fine to be paid:-