"Roland Perry" wrote in message
...
In message , at 13:35:51 on Fri, 16 Sep 2016,
tim... remarked:
They could just as easily have implemented a hybrid scheme with a few
lanes taking payment.

Bearing in mine that there is an exit/entrance slip immediately
before/after both ends of the crossing and there are a lot of people who
need to place themselves in a particular lane to use that slip, and then
there are a lot of people who need to make sure that they are not in that
lane so as not to inadvertently get trapped into leaving the M25 when they
don't want to this would mean payment booths on both the inside and the
outside of each direction.

It would be a nightmare of weaving cars as people who wanted to/didn't
want to pay cash realised they were in the wrong lane

None of this was a problem when the choice was Dart-tag or cash.

that's because there were no special lanes for dart tag

you just drove though a normal booth and the barrier opened without you
paying

tim