From next month we will be resuming the tradition of rotating the monthly newsletter around the regional vice-presidents to present a wider range of views. However, because I was a bit slow in getting this organised, this month’s newsletter is again from me.
Since December, the weather in New Zealand has been superb with warm sunny days (temperatures in the mid-20s) and almost no rain. It is now getting to the stage where a week or so of rain would be welcome to “green” up the countryside and the city gardens. Because of the cooler spring the pohutukawa trees (New Zealand’s Christmas tree) were a little late flowering but when they did they were spectacular. Flowering starts in November and lasts through to mid to late January. Those of you who will be attending HVTT14 in New Zealand next year should be able to see them in flower.
Because Christmas falls in summer here, for most people, the Christmas-New Year period is a holiday. Many people take their annual vacation around this time and for this reason it is a time when there is a lot of traffic and consequently a high-risk period for road safety. For road safety the “holiday period” is defined as from 4pm on Christmas Eve until 6am on the first working day in January. January 1st and 2nd are public holidays and so this year the end of the “holiday period” was January 5th. During the holiday period the police normally run some kind of safety campaign and the number of fatalities occurring during the period are widely reported in the press. For the last two years, the police focus has been on speed enforcement and they have reduced the tolerance they allow before issuing tickets from 10km/h to 4km/h.
There are some issues with this narrow focus on the holiday period. The public and the press understanding of random processes is rather limited. New Zealand is a small country and so the number of fatalities that occur in a short period like this is relatively small and will vary quite a lot through normal statistical variation. In 2012/13 there were 6 fatalities which is the lowest figure recorded since records for the holiday period began in 1958/59. The 2013/14 figure was 7 fatalities and the 2014/15 figure was 17 fatalities. This is a substantial increase and would appear to indicate that something is going badly wrong with road safety. However, if we look at the historical record over the last 25 years we see that quite large fluctuations can occur from year to year even though the underlying trend is downwards. Thus, although the high fatality level this year is a poor outcome, it does not necessarily indicate any fundamental problem with the road safety improvement program.
Why does this matter? A number of commentators have suggested that this year’s fatality rate indicates that the police enforcement program was not effective. To some extent, the police contribute to this view, because, in previous years when the outcome has been good, they have claimed that their enforcement program was effective in delivering the outcome. In my view, an effective road safety strategy requires buy-in from the motoring public and so it is important that the public understands what works and what doesn’t based on evidence and sound statistical analysis. Simply looking at the fatality rate over a short period in December and January does not provide reliable evidence one way or the other.
John de Pont