If we're going to have vigourously enforced speed limits, then perhaps we should have limits appropriate for the roads rather than politically motivated arbitrary figures? Blanket 20mph has more to do with greenwashing and promoting cycling these days than it does with safety. No doubt I sound like some rapid libertarian petrolhead for suggesting such a thing, but even the DfT is starting to reduce speed limits on trunk roads for air quality reasons rather than safety ones. Ergo, vigoruously enforcing speed limits won't be hugely effective in reducing fatalities.
Given the vast amount of people driving whilst texting I see these days, surely a focus on that rather than enforcing an arbitrary figure would be more appropriate?
Also, targetting otherwise law abiding citizens is lovely, but something more effective needs to be done with those people riding mopeds dangerously without number plates, or on stolen vehicles or in cloned vehicles none of whom can be touched by sending a letter to a registered keeper.