The M4 is the bane of many commuters' lives and a huge frustration for many businesses. Crashes bring the road to a standstill often several times a day while queues are simply a fact of life at any busy time of day. The question that many are now asking is: How much damage will it do the Welsh economy in the coming decades, and how many disruption and anguish will it cause, following the Welsh Government's roads review's recommendation to scrap all planned work to improve it?
Businesses who spoke to us said that the problems on the M4 put them at a "competitive disadvantage" to the rest of the UK, that the time they had to allocate for using the M4 cost money and that it discouraged them from locating work at their Welsh plants. Commuters described the road more plainly as a "joke". Many have little faith in the hope expressed by one of the academics who worked on the roads review, who told us that that taking a "broader view" of transport demand could take many vehicles off the M4.
Problems on the M4 don't start and end at Newport. There are capacity issues right across the stretch through Wales and the Welsh Government's roads review, published last week, seems effectively to rule out hopes of increasing capacity at any of its pinch points as a way of addressing those issues. The criteria for future road building suggest this will now simply never happen.
