I am looking at ways in which a heavily polluting taxi rank near a train station could reduce its pollution footprint. My first thought was that the pollution was mostly down to idling and I am thinking of various ways to tackle idling by taxi drivers.
Another reason for the pollution, the reason for this question (and possibly a larger source of the pollution than idling) is the constant 'edging forward' caused when: as each taxi at the front of the queue leaves after collecting a passenger, all the taxis in the queue move forward by one space and then stop. Sometimes there is a queue of 30 taxis and each taxi may move forward and then stop 30 times for every single customer they collect.
This 'edging forward' behaviour encourages the taxis to keep their engines running at idle because there is less time spent stationary. It is also less efficient edging forward in this way than if all the taxis moved forward by a larger degree every time they did move.
I was wondering whether there are any specific solutions to prevent this 'edging forward' behaviour in a queue of cars that would apply to a taxi rank?
(of course any other areas, ferry terminals for example or manual toll booths may also benefit or provide a solution).