Courses and fixed penalties are usually offered in accordance with the Association of Chief Police Officer’s (ACPO) guidance. This was drawn up in 2011 and was adopted by the National Police Chiefs’ Council when the ACPO was abolished in 2015. All forces in England & Wales are said to use the guidance. Similar thresholds are used in Scotland, but courses are not offered there. The guidance can be found here:

library.college.police.uk/docs/appref/ACPO-Speed-E...f

Paragraph 9.6 includes a table showing the various thresholds. So, for example, where the limit is 70 mph, enforcement normally begins at 79mph (Limit + 10% +2mph). Between that speed and 86mph (Limit +10% +9mph) a course may be offered if the driver is eligible. Beyond that and up to 95mph a fixed penalty may be offered. Above 95mph will see court action.

These thresholds are normally followed regardless of the vehicle involved though the police always have the discretion to prosecute through the courts if they see fit. There is no appeal against their decision to prosecute as courses and fixed penalties are offered entirely at their discretion.

If a driver is prosecuted in court, the normal sentencing guidelines are adopted. These are here:

www.sentencingcouncil.org.uk/offences/magistrates-.../

They are fairly self-explanatory apart from the fines. “Band A” is half a week’s net income; “Band B” is one week’s bet income; “Band C” is 1.5 weeks’ net income. Fines are reduced by a third for an early guilty plea. The maximum fine for speeding is £1,000 or £2,500 if on a motorway. That is the maximum before any discount is applied. Courts have the discretion to increase the fine and the points/length of ban beyond those recommended if there are aggravating features. As you can see, speeding in an LGV. HGV or PSV is seen as an aggravating feature.

Hope this helps.