In message , at 23:12:44 on Sat, 13 Oct
2012, D A Stocks remarked:
The closest I came was saying that the original project lost money,
and the two councils would not have had the resources to build the
bridge. (Doubling the capacity for a second time, quadrupling the
original project).

Construction of the first tunnel started in 1938. It was always seen as
part of a project to allow road traffic to bypass central London since
at that time the only alternative fixed river crossing designed for
anything like modern road traffic was Southwark Bridge.

Before the Dartford Crossing we (as residents of Mid Essex) would
normally use the Blackwall Tunnel [doubled in 1967, so was under
construction at the same time as the first Dartford Tunnel], and
sometimes Rotherhithe Tunnel.

Further: since the increased traffic was due to the M25, a government
project, and not increased use by Essex and Kent ratepayers, I think
it was right for the government to take over the responsibility
(which they then outsourced to a private company).

I understand there is a scheme that allows local users discounted use
of the crossing.

Only from the most recent charging scheme (introduced in 2008), it's a
discounted DART-tag. (And all DART-tag users get 1/3 off the car cash
price).
--
Roland Perry