Approaches The Courts Use To Interpret Statues
There are actually five rules for interpretation statues, but only four are mainly used. The reasons that statues or acts have to be interpreted are because, although there are as many as 60 or 70 new acts passed each year  , there are many old or unclear laws. Since we became a member of the European Union (EU) there are in several different languages which can make it difficult to understand the literal wording of the acts themselves due to translation etc.
The Literal Rule means that the court would read the act and take the words at their plain and literal meaning and rule accordingly. The plus side to using this rule is it limits the role of the judge and doesn’t allow them to use their own prejudices and opinions It also recognises that parliament is the supreme law maker (before we joined the EU) and it keeps the separation of powers, However, it can create disagreements as to what “plain ordinary" means, as well as creating create loop holes in the law. It can also lead to injustices as in the case of London and north Eastern Railway V Berriman (1946)  ; which undermines the public’s confidence in the English law and legal system  . It also fails to recognise the complexities and limitations of the English language.
The Golden Rule has two approaches, the broad and narrow approaches. With regards to the narrow approach the court would take the words at their plain ordinary meaning as in the Literal Rule but only if it does not cause an absurdity. The broad approach is as above as long as it does not cause an affront or conflict with public policy, like in the case of Re Sigsworth (1935)  . On the plus side this rule means that if there are errors in the drafting they can be corrected immediately, it can also close loopholes and often gives a more just result. The decisions are generally more in line with the original intention of parliament when the statue was written.  The down side to this rule is that judges are able to add or change the meaning of statutes and thereby becoming law makers which as they aren’t elected it can look unfair to the public, making it look like they have twisted the law to an unjust result.
The Mischief Rule is the oldest used by the courts and came about in Heydon’s case (1584). In Re Sussex Peerage where it was said that rule should only be applied to a case or law where there is an ambiguity. Under the mischief rule the courts role is to suppress the mischief that the act is aimed at and advance the remedy.  There are three conditions that must be satisfied they are:-
It must be possible to work out what the mischief was
It must be obvious that parliament failed to deal with the mischief
It must be possible to define additional words to close any loop holes  .
The advantages of the rule are that it can close loopholes, like the golden rule, and it allows the law to develop and adapt to changes and needs in society. The disadvantages are that it could create a crime after the event as in Smith V Huges (1960)  . It also give judges a law making role and infringes on the separation of powers thereby allowing judges to bring their prejudices, own views and sense of morality to a case. 
The Purposive Rule is used when the court must decide what the purpose of the act was, what the government hoped to achieve with the act in question as the case of Cheeseman v Director of Public Prosecutions 
The Teleological Rule is used for wider interpretation and is used to look for the spirit of the legislation and its aims. It is mainly used for the interpretation of European statutes as the problems with translating.
An explanation of why the fact that Britain is a member of the European Union changes the way in which statutes are interpreted
The fact that Britain is a member of the European Union (EU) changes the way statutes are interpreted, this is because we signed the Treat of Rome in 1973 and agreed that various EU rules would be made law for our country, we also agreed that the European Court of Justice (ECJ) would be the highest court and that EU law would be placed above law made in this country.
So now when the courts are interpreting statues EU law is taken into account so that one does not infringe on the other. This means that the purposive rule is used a lot to make sure that EU law is well interpreted before the courts can interpret the English law because if it is not then it could leave for appeal in the ECJ where its decisions are binding on English courts  . In becoming a member state of the EU each country transferred sovereign rights to European Union Law so European Law has supremacy over national law  .
An explanation of why Judges need to interpret statutes and the possible problems that could occur
The reason Judges have to interpret statutes is because there can be many problems with acts. These can be Old language, Ambiguity, spelling, draft and grammar mistakes. There are different things a judge could use to aid them these are called Intrinsic and Extrinsic aids. Intrinsic aids are those contained in the statue itself and consist of  :-
The long title of the Act
Other sections of the Act
Definition sections in the Act
Rules of language
Presumptions are used when a statue does not fully provide otherwise so it is presumed the following apply:-
Statues do not effect the monarch
Statutes do not operate retrospectively
Excising rights are not to be interfered with
Statutes do not change the common law
Mens rea is required for criminal liability 
There are three rules of language and these are:-
Expressio unius exclusion alterius (The mention of one thing excludes others)
Noscitur a sociis (a word is known by the company it keeps)
The first rule means that there must be at least two specific words in a list before the general word or phrase, for this rule to apply  i.e. a statute which states it applies to lions tigers cheetah and other animals would apply to leopards but not to a horse as they are not of the ‘like of the others’ in the list  . The second rule mean that because there is a mention of one thing excludes any others of the like i.e. I could allow animals into my house but I specifically add dogs only, I would not allow any other animal into my home other than dogs.
The third rule applies when there is a list of items in the statute the item under consideration could be included into the list but because of the context of the items suggest that the item should not be in the list, for example if the statute stated it applied to cat baskets, toy mice, flea collars and food under this rule a loaf of bread would not be with the remit of the statue because it does not relate directly to the other items in the list. 
Then there are Extrinsic aids which are things like:-
Law commission reports
Case law from other jurisdictions
European Convention on Human Rights 1950 or the Human Rights Act 1998  .
Case Law is law that was made as a result of a previous crime and trial, where the judge’s decision makes law that other judges have to follow  . The disadvantage of this is it gives judges law making power and they are not elected by the public so it does not always appear fair, as parliament is an elected body.
An explanation of the impact the Human Rights Act 1998 had on statutory interpretation
When England signed the Treaty of Rome in 1973 we agreed that we would accept that various rules, regulations and directives which would be made law in our country. The best example of this is the Human Rights Act 1998 (HRA), which came about due to the European Convention on Human Rights 1950 (ECHR). England picked out certain directives and legislation of the ECHR and put them together and called it the HRA  . It is the first time legislation has been brought into effect which gave something as apposed to not allowing us to do something.
It is stated in the HRA in Section 3 of the Act which is Interpretation of legislation ‘so far as it is possible to do so, primary legislation and subordinate legislation must be read and given effect in a way which is compatible with the Convention rights.’ This would apply to any case where any of the rights are concerned. So for example if the conclusion to a murder case was that the convicted was to be sentenced to death then it would be in violation of their Human Rights were they are entitled to life it would be an incompatibility therefore creating the need for a declaration of incompatibility which is Section 4 of the HRA  . So when ever a judge is interpreting statutes they have to make sure that it was not in fringing on the HRA or the ECHR because English Law is bound by European Law and if it does than it could mean that a decision could be revoked.
Case Study of Alison
I feel that Alison would have no grounds for appeal as the statute clearly states that ‘thoroughfare’ means any road pavement or other similar place along over or through which vehicles or pedestrians pass and as she was walking on a foot bridge over a main road and it would come under the term ‘thoroughfare’. The European Union Directive also mentions public place which she was in. The purposive rule could be used because the whole point of the act is to stop people smoking and is clearly stated in S2 (2) what is meant by thoroughfare, so she would have to pay the fine not exceeding five hundred pounds. If however she was arrested before the act was brought into effect then she could not be held to have broken the law.