How would you feel about a 50 mph motorway speed limit to tackle pollution?

Should we be limited to 50 mph in our cars, in an attempt to reduce air pollution? The limit was reduced on the motorway and on stretches of A-road in December in Wales - and now the Welsh Government has now confirmed the restrictions will stay permanently. Should we be forced to slow down to improve the air we breathe? Stephen got the views of writer Tim Hedgley and commentator Dave Atherton.