The term �low end� is not one officially recognised and as such has no defined meaning.
The Association of Chief Police Officers (ACPO) have issued guidelines to help their officers and fixed penalty offices decide how to deal with speeding offences. Firstly, they have limits under which no action is normally taken. These are:
20mph limit: 25mph
30mph: 35mph
40mph: 46mph
50mph: 57mph
60mph: 68mph
70mph: 79mph
This does not mean it is legal to travel at these speeds. Prosecutions below these levels are not normally undertaken to avoid arguments about instrument calibration and so on.
Above these speeds, firstly consideration for a fixed penalty (�60 and three points). This is normally offered up to the following speeds:
20mph limit: 35mph
30mph: 50mph
40mph: 66mph
50mph: 76mph
60mph: 86mph
70mph: 96mph
A fixed penalty would not usually be offered if there are aggravating features (such as a collision where excess speed may have been the cause) and would certainly not be offered if three points would take the driver to twelve or more and thus make him liable to a �totting� disqualification.
It is interesting to note that if prosecuted in the magistrates� court, a motorist faces more than the magistrates� minimum fine (half a week�s income) and minimum points (three) before the above limits are exceeded. For example, in a 70 mph zone a FP is usually offered up to 96 mph. If you appeared in court charged with the same excess speed you would face a fine of one week�s income, 4 or 5 points or possible immediate disqualification up to 42 days.
Speeds above those in my second table are usually dealt with by way of summons to the magistrates� court.