From his first days in the job, Scotland's chief constable made road safety a priority.

With the number of road deaths now four times the murder rate in Scotland, Sir Stephen House said cutting the number killed in collisions and accidents was one of his top-three priorities along with violence and anti-social behaviour.

Prioritising road safety in this way is a perfectly fair and achievable priority, but its implementation out on the roads has not always been received well. In the early days, there was concern, inside and outside Police Scotland, that a target culture was developing and that officers were no longer able to exercise discretion in certain cases. The impression that the rules on seat belts and speeding were being applied indiscriminately, even though it was untrue, also risked undermining the public support on which good policing relies.

The reality is that police officers have always been able to exercise their discretion, but an adjustment was needed after the creation of Police Scotland. In the old days of separate forces, traffic laws were applied with different degrees of vigour in different parts of the country, but a view was taken at the top of the new single force that this could not continue. It meant that in some areas, in circumstances in which officers might have issued an informal warning, they were now issuing tickets.

Then, in a subtle change of policy last year, perhaps in response to the criticism, Sir Stephen revealed traffic officers were issuing fewer tickets and issuing more verbal warnings instead. Now a six-month pilot is extending the policy but changing the nature of the warnings. After receiving permission from the Lord Advocate, Police Scotland has won the right to hand out formal warnings in circumstances in which the driver would not normally have been ticketed - for example if they are within the normally enforceable level of 10 per cent plus 2mph over the speed limit.

On the face of it, this might look like a policy that will affect many more drivers who would have expected to have received an informal warning, but it is only a pilot at this stage and will apply in particular spots where offending is high or accidents are common. The police officer also retains his or her discretion and if someone is caught speeding within the 10 per cent and 2mph limit, there will remain a range of options: informal warning, a ticket, or the new formal warning.

What kind of effect the formal warning is likely to have is hard to predict at this stage, but the fact it will stay on your record for some time and increases the chance of being prosecuted should you be caught doing the same thing again means it has the real prospect of changing behaviour. And that, along with catching offenders, should be one of the underlying principles of good policing.

An alternative might be to simply book everyone who goes over the speed limit, but the danger of that kind of literalism is that it will enforce the erroneous belief that the police have targets and that the incentive is money (in fact, Police Scotland does not keep the proceeds of tickets). Issuing formal warnings instead helps emphasise that the aim is not to make money, but to change the way motorists drive and to make accidents less likely.

As a possible step towards that aim, the new pilot scheme is to be welcomed. Speed awareness courses should also be considered as another possible strategy. A formal warning avoids criminalising generally law-abiding citizens who have a momentary lapse of judgment, but it could also reduce irresponsible driving and save lives.