There are some cones running in between the lanes on the A1 north bound, the kind that fit over the cat’s eyes and keep the traffic apart. I think they are called lane separators but I may be wrong and they are orange, a couple of feet high and have a small reflective silvery-white jacket. They start from just outside the Washington services and wind down the Bowes incline before petering out at the bottom of the hill at the end of the Team Valley trading estate. I gather that they are there for some overnight work and allow the road crews to close one lane or the other but during the day traffic can flow down both lanes but cannot cross between the two.
So the road is the same width as normal during the day and both lanes remain open and so the rate of flow should be the same as any other day yet the traffic has been queuing back much further than normal in the morning rush hour. When I head south towards work it is not uncommon for there to be traffic backed up as far as the Chester le Street junction but in the last few days it has stretched back to Durham, a good few miles further. There must be around a thousand more vehicles stuck in the jam and of course I am intrigued to know why.
Clearly the inside lane has to deal with all of the traffic that is trying to join the motorway from the two junctions within the roadwork area but this is normal and there are no apparent increases in the amount of vehicles using these roads. This is not the case with the outside lane however where there are no obvious obstructions and traffic is free to flow continuously. But it doesn’t, the traffic judders along in the outside lane just as if traffic is still joining from the slip roads whilst the inside lane grinds between dead slow and stop.
The only difference is the line of lane separators down the middle of the road and so why the trouble? I have two theories. The first is that the road is normally a self organising system where individual drivers choose to move between lanes, leave and join at junctions all dependent upon the state of the traffic at a given point. These decisions help to ease flow as the greater the congestion the greater the lane switching and the greater the amount of drivers that will leave the road and find an alternative route. The inability to switch lanes prevents any self-organising.
The second is that many of the drivers are unsure about the roadworks and which lane to stay in. Can I get off at my junction? Which lane is going to be quicker? Should I change now or will it be too late? All of these decisions take time, albeit a fraction of a second but if all of these fractions, these hesitations are added up they can amount to a significant accumulated delay or a noticeable reduction in the rate of traffic flow hence the backlog.
I might be right or I might be wrong but if anyone has any better ideas I would be intrigued to know. The real question however is why I let such things exercise my mind.
Thoughts from a Guerrilla Worker 