We’ve previously looked at how so-called smart motorways have increased their remit from merely managing congestion to fining speeding drivers too - and this is something they are very good at: the BBC’s One Show looked into this and the results were shocking.
It found that more than 1,000 speeding motorists are being caught and fined every week along just 11 sections and 236 miles of smart motorway.
In total, 52,516 fines were issued in 2015, a rise of more than 50,000 since the introduction of the first smart motorway in 2010-11 - and it’s not going to slow down any time soon.
The UK government is pressing ahead with its plans to spend a further £6b on upgrading the motorway network, with a spokesperson saying: "Smart motorways smooth traffic flow and cut congestion for millions of motorists, with evidence from trials showing they are just as safe as regular motorways.
"Enforcement is a matter for the police and it is clear that speeding costs lives. However, we have been clear for a number of years that speed cameras should not be used to generate revenue."
Despite this apparent confusion as to a smart motorway’s role, there are things you can do to fight back.
Find out more: Cameras to issue speeding fines on smart motorways
Obeying the speed limit
Of course, obeying the speed limit is the single greatest thing you can do to beat the system, but it’s important to understand what the speed limit actually is in the first place.
When the overhead gantries are displaying a speed, they do so in one of two ways.
The first is simply a number, while the second is a number with a red circle around it. Only the latter – a number with a red circle around it – is mandatory, and should be adhered to in the same way you would adhere to the speed shown on a metal road sign.
Without the circle it is merely advisory, based on factors like weather conditions, and can be legally ignored.
Whether you should do so is a matter for your judgement and conscience, rather than an act that will trigger a fine and points on your licence.
Speeding myths dispelled
HADECS 3 speed cameras
The HADECS 3 (Highway Agency Digital Enforcement Camera System) speed detection camera are always live. This means they’ll dish out a fine for exceeding the 70mph speed limit even when a lower limit isn’t displayed.
You might think that this runs contrary to the stated aim of smart motorways, which is to “smooth traffic flow and cut congestion” but at least you now know what you’re up against.
Ever wondered 'What is that thing on the side of the road?' Find out now!
Average speed cameras
There is some confusion among drivers as to exactly what an average speed camera measures: It does not measure your speed at the point at which you pass the two cameras and then averages that reading between them, something that three different people have said to me recently.
How they actually work is very simple: average speed cameras measure the average speed of a vehicle between two fixed points. The system starts the stopwatch when you when you pass camera A, and stops it when you pass camera B. It knows how far apart the two cameras are and so can easily calculate how fast you have just driven between them.
If you have exceeded the speed limit by a set margin - an element of discretion is almost always built in to avoid snaring drivers who have only edged above the limit by a small amount due to calibration errors or momentary inattention, although the precise amount can vary - it automatically generates a ticket for speeding.
But knowing exactly what is being measured helps us avoid triggering a speeding fine accidently; if you inadvertently pass an average speed camera at a higher speed than you should, you can lower your overall average by immediately reducing your speed.
Doing so quickly enough, and by a sufficient margin, will increase the time taken to reach the second camera and so reduce your overall average between the two.
You shouldn’t ever rely on this – speed limits are there for a reason, obviously – but a momentary lapse of concentration can be compensated for in a way that isn’t possible with other sorts of camera!
Five secret driving tips from a chauffeur
Don’t ignore the ‘X’
Finally, an ‘X’ above a lane means that that lane has been closed and that you must not drive in it. If you do, then the likelihood is that you will be fined.
Please don’t ever ignore a red ‘X’ lane closure in an attempt to shave a few seconds off your journey time because there is almost certainly an obstruction ahead.