Mr Lenthall on measuring the success of the highway system in Stevenage
Mr Lenthall discusses the different ways they tried to test the success of the highway system- from balloons, to helicopters, to cine cameras.
After we’d put down the system and it had been operating for a few years, there was a lull in our programme of engineering construction, and we thought, here’s a fine time, we’ll now go out and measure our highway system and see how successful we’ve been. And for that purpose we set up a research and planning section, and a senior engineer, assistant chief engineer John Jones. And the first thing we did was to find out exactly what sort of movement was taking place. We had all sorts of fun; we tried to film the entire highway system moving under peak hour conditions. We thought at first we could put a camera in a barrage balloon, but that turned out to be not a stable platform, so then we resorted to a helicopter, and we actually flew over the town at peak hours and tried to take a film of the traffic moving, but there was a certain amount of vibration in the helicopter. And then about this time somebody introduced us to an autographic recording system. You use your rubber tube across the road, which produces little pulses of air out of the counting machine at the side, and the particular machines we used produced a circular chart, a flow chart. And also somebody else introduced us to cine camera technique – I think it was Bedfordshire County Council, who were doing some experimental work on trying to understand the problems of heavy lorries on motorways on inclines – and they were using cine cameras and the time lapse technique where you film at one speed and then you look at the film at a faster speed, characteristics begin to emerge. And we used these two systems to try and understand exactly how people were using the highway system.