In message , at 10:50:11 on Sat, 15 Dec
2018, tim... remarked:

the phone and postal services for the Dart Charge seem quaint and
indulgent compared with the toll roads in eg Sydney where it's
electronic or else - including for visitors in hire cars.

The postal service is only for pre-pay, and needs 10days notice. I'd
characterise it more as applying for a season ticket by post (even if
it's only a one-trip season being paid for).

I wonder if it's mainly for institutional vehicles, where
arrangements for reimbursing drivers small amounts of money are
either non-existent or very clumsy, and they don't want to have a
system for drivers to report each trip as it happens, and the finance
department pay the charge from central funds rapidly enough.

surely if the institutional vehicle belongs to the institution, they
can set up an online account that does all this

Many institutions are leery of online accounts, many of which appear to
them to be akin to blank cheques. I'd be surprised if a school (even one
in Essex or Kent) was happy to set up an online account for even the
Head's car, should he have some official business the other side of the
river. How would that account not end up also paying for his leisure
trips, for example? The postal payment, however, could be ringfenced for
just one trip.
--
Roland Perry