We have seen with the M6 Toll that drivers can be turned off by the imposition of charges. There is already a toll to get into Wales on the Severn Crossing but no toll to get out.
There is no doubt that the M4 around Newport needs improving. At the moment if there is a bad accident and the road is closed there is no real alternative for drivers.
But if the road is tolled it reduced its economic effectiveness as a lot of people will be put off using it and will simply avoid it.
More top news
Today's rain will clear into the North Sea tonight, but winds will stay strong, with showers feeding in to the north and west.
EastEnders fans could be seeing double after the show’s bosses announced they are looking for a new actor to take over the role.
Dozens of flood alerts have been issued for swathes of the country as heavy downpours and severe gales are expected.