Driving instructors are over-rated; and other driving licence data analysis

Considering nine years of practical driving test results (2005-2013) across Queensland, those that used a driving instructor (driving school vehicle) had a barely discernible improvement in pass rate over those who used private vehicles.

 

The Queensland Government publish practical driving test results (www.data.qld.gov.au). As part of this data set they record if the test was taken in private vehicle or a driving school vehicle. I assume that if you take the test in a driving school vehicle then you are likely to have been coached by the driving school. Their primary job is to teach you how to be a good driver, but also to prepare you for what to expect in the practical examination.

From 2005-2013 there were just over 125,000 individual driving tests across Queensland. Of those 125,000; 49% passed, and 44% of the tests were conducted in driving school vehicles (56% in private vehicles). I was expecting to see that those tests conducted in the driving school vehicles would far outperform those conducted in private vehicles.

My assumption is that if you show up for the test in a driving school vehicle then you have probably have had at least some coaching from a professional driving instructor. In my opinion, a professional driving instructor should do a much better job at training you to be a good driver than your terrified parent. On a state-wide basis there is no real difference in pass rates (Driving school =49.5%, Private=48.7%) (final column in Figure 1). So YEAH to the great job that parents do in going through the white-knuckled-terror of teaching their kids how to drive.

 

Figure 1: Practical driving test pass rates for Queensland (2005-2013). The number of tests conducted for each region are shown in brackets.

Country vs City?

There are some differences in success rates between the different regions (Figure 1). I haven’t checked for statistical significance, however Figure 1 seems to illustrate a higher pass rate for some of the regional centres (South West, Mackay and Wide Bay Burnett). Consider the South West region (far western Queensland) where if you use a driving instructor you have a 74% chance of passing, compared to Brisbane where you have only around a 42% chance of passing irrespective of private or driving school training.

This extreme result is not likely to be that representative, as there are only 6.5% of tests in the South West carried out in driving school vehicles. I guess that this is due largely to the limited number of driving instructors in small remote towns. Even considering the use of private vehicles for tests in the South West region (64% pass rate) you have a 20% greater chance of passing than in the main metropolitan areas. Presumably this is partly due to country folk having had a lifetime of on farm driving experience before they go for their licence. Maybe country drivers are simply better than city drivers!

Manual vs Automatic?

In Queensland you can be licenced to only drive automatic vehicles. In fact 49% of vehicle driving tests were for automatic vehicles. The pass rates are very similar (47% for automatic vehicles, 51% for manual vehicles) with no discernable advantage by going through a driving school for either transmission type. If in doubt, go for a manual licence so that you at least have a valid licence when you borrow your mates ute to move house.

Does age matter?

I expected a huge proportion of driving tests for 18 year olds. Figure 2 shows the five year age cohorts, and yes the 16-20 year cohort is the biggest, accounting for about 25% of tests. But it seems Queenslanders are in no hurry to get their drivers licence. Interesting we seem just as likely to engage a driving instructor whatever our age as shown by the blue bars (37%-46% of tests across the ages). If we just consider the major metropolitan regions in south east Queensland to make our plot a little easier to read. Figure 3 looks pretty dramatic (thanks partly to the graphing trick of not starting the y axis at zero), especially for Sunshine Coast residents where their pass rate starts at 33% for 18 year olds and peaks at 54% for 40 year olds. The trend is pretty similar across all the metro areas, so yes age does matter and older is better. As a grumpy old man I am heartened by this result – with age comes experience, patience, and wisdom (sometimes) – all good traits for a driver – as well as an increasing contempt for those younger than oneself.

Now you should either thank your parents for being good teachers or be anguished over the money you wasted on a driving instructor. Drive Safely.

 

Figure 2: Distribution of driving tests across ages

 

Figure 3: Does age make a difference?

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