Police should definitely have discretion when it comes to ticketing and enforcement.
In theory, this should allow for leniency when warranted and avoid creating extra work.
This in turn would allow more time to focus on truly dangerous drivers.
But if reports that many motorists are being ticketed for travelling slightly over the limit, including while passing other vehicles, are true, then that discretion is being abused.
Discretion is important, because not all roads and highways in New Zealand are the same, and motoring conditions are always going to be different - be it traffic, weather, time of day or other.
In the past there's been a clear, though perhaps unspoken, tolerance of either up to 10km/h, or over the past couple of years, 4km/h during holiday periods.
Maybe some people set their cruise control to the tolerance limit, as Mr Bush has noted before, but for many motorists the tolerance just allows a bit of breathing room around the limit.
It meant you didn't have to keep your eye on the speedo to make sure you hadn't drifted one iota above 100km/h.
And of course police still had discretion to crack down on dangerous driving.
Yes, having varying tolerances is its own form of mixed message. Either the limit is the limit or it's not.
But absolutes and zero-tolerance policies can create more problems than they solve.