Welsh Government is considering tolling parts of the M4 and A470 to discourage older vehicles emitting harmful nitrogen dioxide.
It has surveyed users and asked how their travel plans could change if cars were charged between £3 and £8 and light vans £6 to £12.50 with lorries up to £50 a day to use the M4 around Newport and A470 at Upper Boat where 50mph limits have been introduced to slow traffic and reduce emissions.
Environmental groups have said the Welsh Government is not doing enough to meet obligations on cleaner air and the 50mph zones have failed while opponents to the charges are concerned they will disadvantage poorer sections of society who have to use the roads for work and face higher costs which deter them from getting greener vehicles.
