Tuesday, January 29, 2013

Are taxi drivers really that dangerous?

AsiaOne Motoring reported that taxi drivers were either dangerous or just unlucky, as they accounted for 14% of accidents, but formed 3% of the vehicle population in 2009, as shown in the chart below:

Source: AsiaOne Motoring
However, taxi drivers spend longer hours on the road, and would naturally be involved in a more-than-proportionate number of accidents. A fairer way to assess them is to look at the number of accidents per km driven; how do they fare in this regard?

Using data from the Land Transport Authority, and also noting that about half of taxis are on double-shift, I found that each taxi gets a mileage of about 84,000 km per year. Now, that is quite a lot considering that the average mileage of other vehicles amounts to about 21,700 only. Furthermore, this 84,000 km is an underestimate since the data only includes distance travelled with passengers, but not the distance incurred looking for passengers.

Hence, with at least 3.9 times more mileage, are taxis four times more likely to get into accidents?

As mentioned earlier, a fairer way to assess taxi drivers is to estimate the number of accidents per km. On this count, taxis  incur 10.6 accidents for each million km on the road, much higher than the 7.3 for other vehicles.

The accident rate for taxis, however, is overestimated since I did not include mileage incurred looking for passengers. I'm not sure how much mileage empty cabs register, but an answer that sounds right to me would be 3 out of every 10 minutes on the road. If so, the accident rate for taxis is 7.4 per million km, practically the same as that for other vehicles!

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