[Bibio]

like all traffic systems its not the road structure that is at fault its the people driving on them.

smart motorways (lets call then "increased lane") are no more dangerous than dual carriageways.

one of the biggest factors of congestion is narrowing at end point but there is nowt we can do about the cities and towns road structure apart from turn everything one way and open up disused railways as "relief roads" instead of cycle/walk ways or build "stilted roads". or build inner city trunk/access roads at the end of motorways. that way traffic can filter into areas as it goes. but that would mean destroying peoples homes.