The next time you see a mass of tape and wires fixed to the road at a junction in Dubai, you'll know what it is. The city's transport agency uses the crude-looking devices to measure data including speed, the distance between cars and the number of vehicles. Dubai's Roads and Transport Authority responded to questions from puzzled drivers on Twitter, describing the units as "traffic counting devices". In Europe, devices that resemble black rubber tubes are more commonly seen on the roads and are not dissimilar to the footfall counters often placed at shopping centre doors or on high streets to record shopper numbers and retail behaviour.