I find myself watching and laughing rather sadistically. Why? Because the traffic lights of a major road junction by our house have malfunctioned and gone dead.
The street running close to our house is the equivalent of a road estuary. 3 lanes of city traffic (not including the cycle lane and two paths) normally comes to rest at the traffic lights in a 5 lane queue and the lights control the traffic that crosses 3 lanes of fast moving ring-road traffic in each direction (a total of 6 lanes). Normally, it all flows remarkably well and quietly, albeit much more slowly than before the launch of a new but faulted public transport system.
But this afternoon, i can hear, in glorious stereo, the sound of traffic light failure. Nobody quite knows what to do. The local council security guard stands on his motorbike and scratches his head, or rather, types away at his mobile phone in frustration. Street sellers look on with some delight at the ensuing chaos. More stationary traffic means more sales.
However, for the drivers, it is a battle of the wits- who will stop first? who will let the traffic through? how much horn punching will slow an articulated truck? will the bus stop?”
Well i can answer the last question with a resounding no- the bus won’t bother to stop.. he’ll just push on through one, two, three, four lanes of traffic. The truck? Well being a rather large animal and less able to stop in an emergency, the drivers seem quite sensible, slowing and even stopping to allow traffic to pass. Of course, once a truck stops, the other two lanes are safer to stop too, especially since their view is obscured.
Oh, what a nice Freelander driver…. (yes, i’m still watching). Nissan truck drivers are the equivalent of our white van man; the least considerate of either his lane or any other road user! Another driver (of a volkswagen) has just discovered his horn will endure consistent pressure for at least 20 seconds. It’s going to be a long, noisy rush hour!
From a theoretical perspective, i find this driver behaviour fascinating- what makes a driver yield to another? Does he consider the other traffic in his lane or the pressure of other drivers behind him? Or does he simply act selfishly and drive on as fast as possible, even though he may be holding 5 lanes of traffic back by this action?
What is the likelihood that by slowing on the approach to the crossing, a driver will tempt a lane jumper to take the lead in wading through the crossing traffic? Or the likelihood that he will find his path blocked by a crossing vehicle who “grabbed the gap”?
The answer, at least through rather amateur observation, might surprise you. “Group think” makes the probability of yielding quite high. One lane can take the initiative in crossing and in doing so, commands the other 4 lanes of traffic moving with him. After the first yield, the other lanes yield easily and almost uncomplainingly.
After the crossing traffic flow reaches a consistent speed, differences in the speed of individual vehicles in the flow produce gaps which allows a driver in the competing flow to (use their horn and) move forward, stemming the flow, one lane after another until a new cycle is set in motion in the direction perpendicular to the first cycle. On average, the volume of traffic without control actually approaches that of the junction with control (i.e. when the traffic lights are operating), but with lower average speeds and (if traffic flows are not equal) longer queues.
Of course, this analysis excludes the random error element (the impulsive, impatient latin american driver element). Including that, I give it 15 minutes until someone loses a bumper and 50 minutes until someone loses their car or their life.
And it’s not even rush hour yet! Mmmmm… the possibilities.
