pay by displacement

Recently the Land Transport Authority has announced the "Distance Fares" for public transport, in which commuters will be paying the fare by distance. Sounds weird, makes me feel like all this while I have been paying something other than by distance.

Not really a new invention, since some other cities in the world have something like free transfer on buses. For example in Hong Kong, especially when you are taking long haul bus services (and yeah, here in Singapore we are talking about eliminating long routes), you can transfer free to other connecting routes at bus stops at tunnels. Personally I found it very convenient while I was in Hong Kong, you don't have to worry about not having a bus heading to your destination.

Now, I am reminded of a physics chapter on vectors and scalars. Should we pay by distance, or pay by displacement? Now our rails are pretty much in loops, if we want to travel from Bishan to Bradell we can either travel 1 stop, or we can go all the way North to Woodlands then Jurong East then Raffles Place then up North again. If I'm not wrong, we will still pay for 1 stop's fare if the travelling falls within a certain period of time. How about on buses? For example, if I want to travel from Ang Mo Kio to City Hall by bus, there are so many options, but some take the longer way. When the "distance fare" is implemented, will we be charged the same for going from point A to B, or will we be charged for the path taken by the tyres?

Sounds like pay by diesel burned.