In message , at 14:19:18 on Sat, 17 Sep
2016, tim... remarked:
You could do that today using ANPR for those regular users with an
account.

1) you'd still need the barrier so that it could remain closed until
the cash payer had paid the correct amount (and in the completely
idiot proof system - received their change)

No physical barrier required, just traffic lights.

but that will still result in a queue

Only for a couple of lanes, and last time I drove over the bridge it was
stop/start the whole way, so this "freeflow" thing is a bit of a myth.

2) how do you determine which punters in the queue are going to post
pay by internet?

By concluding that all those who didn't pay, and didn't have a prepay
account, must be post-pay. Exactly the same as today (apart from the
cash/card payers).

It's not exactly the same as today, as today you don't have to control
a little red/green light for people to proceed

It is the same because you could dispense with the lights and go after
the people who need to post-pay, just like today.
--
Roland Perry