So what will happen when this supply led demand increases and
congestion again becomes as bad as ever? How will the emergency
services cope with no vacant hard shoulder? Let me guess, more
motorway widening/building?

"Work has begun on rolling out a scheme allowing motorway drivers to
use the hard shoulder in parts of the Midlands.

An initiative has been on trial on the M42 east of Birmingham.

There are plans for four other motorway stretches to allow motorists
to use the hard shoulder and or to have variable speed limits at the
busiest times.

Changes would apply at the end of 2009 on the M42 between junctions 9
and 7, the M6 from junction 4 to 5 and the M40 from junction 16 up to
the M42 link..."

More:

http://news.bbc.co.uk/1/hi/england/7619969.stm