The offence is endemic, the fault is the nutty method of building criminal cases via correspondence. It is believed that more than a million people in the country have done the same as Huhne.
More than a third of the population when asked have said they would ask someone to take their points if the alternative meant losing their licence. It's an easy no brainer for most.
It strikes me as frankly ridiculous that the SCPs have been allowed to become agent provocateurs for this offence, ignoring its commission for the most part, them, when evidence strikes, coming down like a ton of bricks.
It's a pointless way of creating serious criminals out of otherwise decent people.
Certainly when it comes to speeding, I think clearer, more frequent, signage would be more effective. After all, if people are expected to keep to a speed limit, it might help if they knew what it was! I've been on a speed awareness course which teaches you to take an educated guess at what the speed limited should be in certain environments - which is all well and good, but there are plenty of anomalies. Since doing it, I still find that it is not immediately obvious what the limit is on some stretches of road (there can sometimes be no advice for miles). More frequent periodic reminders painted on the road surface would certainly give drivers less excuse of not knowing what the limit is (not that that work's as a defence, but I suspect POs tire of hearing it).