Lately there has been some discussion in the Netherlands about the so
called 'kilometerheffing'. 'Kilometerheffing' means in effect that you
get a GPS enabled device in your car. This device tracks where you are
driving and based on that info you will be billed. I.e. you will have to
pay more for driving on busy roads. The average price will be around 3
eurocent per kilometer.
Of course this is an enormous invasion of privacy. Despite the claim
that the GPS data will stay in the car and only will be used in criminal
cases. And despite the fact that the only information the government,
represented by a billing office, will get is how much kilometers you
have driven for a given price. In this blog post I will show with a
simple example that the price per kilometer can be used to track your
People familiar with the road layout in the Netherlands will know that
coming from Leiden I have a few options to get to the A1.
- A44 - A4 - A10 - A1.
- A44 - A4 - A9 - A1.
- A4 - A10 - A1.
- A4 - A9 - A1.
The difference between options 1 and 3 depending on my decision to
Leiden on the east or the west side.
Lets now assume the following pricing scheme:
A44 1 eurocent per kilometer.
A1 2 eurocent per kilometer.
A4 4 eurocent per kilometer.
A9 3 eurocent per kilometer.
A10 5 eurocent per kilometer.
Lets also assume I get the following bill:
A kilometers of 1 eurocent
B kilometers of 4 eurocent
C kilometers of 3 eurocent
D kilometers of 2 eurocent
Is is fairly trivial to conclude I must have driven on the
A44, A4, A9 and A1. So I probably have driven route 2.
Of course this tracking by using prices can be improved significantly.
The major excuse being to regulate traffic. It is easy to argue that the
traffic is more dense on Monday morning so the tariff on the A10 should
be 5.005 eurocent per kilometer on Monday mornings. 5.004 eurocent on
Tuesday, 5.003 euro cent on Wednesday etc. Then having a 5.004
kilometer price on your bill would put you on the A10 on Tuesdays.
To further facilitate this way of tracking the innocent I would like to
propose the following scheme for the pricing:
B.WWWDDHHMMKKK eurocent per kilometer.
B - Base tariff.
WWW - Number indicating the road.
DD - The day of the month.
HH - The current hour in 24 hour format.
MM - The current minute of the day.
KKK - The position on the road in kilometers from the start of the road.
i.e. Driving on the 1st of December 2009 at 19:54 CET on the A35
between kilometer 50 till 51 would then cost you
2.035011954050 euro cent per kilometer. This of course also allows for
determining in which direction is travelled. Note that month and year is
not needed, because of the monthly invoicing. Or just maybe we should
put the GPS coordinates in the price.
But the moral of the story is,
datamining on your 'kilometerheffing' bill can tell a lot about your movements by car.