I think a lot of driving standards deterioration is down to the fact that alot of the rules aren't enforced and when they are it's almost in an apologetic way. If speed limits are important (and IMHO they are) then if you are breaking them you should get fined, heavily, no dayglo cameras to spot and avoid, I'm not convinced about the education courses either to be honest. No to only put cameras where there is an alleged accident blackspot (local pressure group / local councillors house), either the speedlimit is appropriate and should be stuck to or it's not which comes onto rant no 2.
Inappropriate speedlimits. Here I'm on the side of the drivers, where have all these 20 mph limits appeared from on through roads? I've no issue with lower limits on residential streets, infact they are a good idea but on main through routes, mental. All it does is get drivers 'used' to breaking the limits and ignoring speed limits where they are more appropriate. This speed limit reduction bandwagon seems to be hitting dual carriageways now as well, sections that were 70 are now down to 50 or even 40.
I think it's time our whole road network was looked at, appropriate speed limits where they are warranted, additional safety equipment, e.g. barriers where speedlimits are higher and pedestrains are likely to be around. Couple with that with a 5 year driving appraisal, don't test the basic mechanics of driving, test the attitude of drivers, should be fairly easy to spot the really bad drivers in a test situation. Everyone drives more carefully when observed so the bad drivers should still stand out and couple it all to more appropriate enforcement, no ambiguious double standards, if you break the rules you get done (just ensure the restrictions are appropriate to the road).
The more we allow people to regularly break the rules and get away with it or the more the media is allowed to denigrate enforcement activities (speed cameras - a tax on motorists my a*se) the more driving habits will slowly worsen at the same time giving drivers an exceuse to justify poor driving, I know I think like that sometimes. It also filters down to cyclists, how often do we hear the justification for poor cycling based on the poor driving standards of car drivers.