This article was published in 2014, in Newsletter 115.
The cycling barometer counts cycles passing around a bend of a cycle path in a corner of Parker’s Piece.
What is it?
The barometer itself is a vertical display board set to the side of the cycle path as it approaches Regent Terrace. It displays the number of cycles counted since midnight as they pass. Another display alternates between the date, the time and the temperature in Celsius. The most barometer-like aspect of the display is a vertical column of green LEDs (light emitting diodes) which display the cumulative total of bikes since the beginning of the year. As the device was installed on 3 July this was pre-loaded with an estimated value, which judging by my photos was about 300,000.
How does it work?
Two metal detectors are embedded in the cycle path, each approximately ten metres from the barometer. Bicycles passing over them produce a distinctive electrical profile which is recognised and counted. The position of the detectors allows riders to see their count being registered on the display board thus acting as a form of coercive positive feedback. The detectors are directional and so the bike is not double counted as it passes the other detector going away from the barometer.
How will the data be used?
The data collected by the barometer will not be recorded as part of the county’s official statistics on traffic flows. There is already a long-established way of counting traffic in the city and this device is not part of that.
The device has primary benefit for cycling as it is an in-your-face reminder of just how many cycling journeys there are daily. The barometer has been sited so that it can easily be seen by the usually queuing motor traffic in Gonville Place.
They expect around 2,500 daily cycle journeys, which equates to almost one million annually. We can apply for the data from the county: it is not available as a feed. Common in other European cycling cities, there are similar barometers already in London and Brighton. The one in Hackney is likely to be the biggest rival.
Most of the money for the project came from the European Union’s Bike Friendly Cities project, with contributions from Marshall’s and the Cambridge News. Their contributions have been recognised on the display board.