there's a hell of a smell developing here - too many coincidences are occurring around sandy lane recently
The lines are traffic counters monitoring number of vehicles and speed they travel at, putting them there at the height of the season give an unreasonable set of figures that the Council can use for what ever they wish.
Which Council? For someone who appears very well imformed you must know what nefarious purposes these statistics will be used for.
If you are so ignorant of the facts, why not ask Devon County Council, if you can have a copy of the results.
If they will not give them to you, or generally make them available to the public, then there will be an air of suspicion surrounding the installation of the blow pipe's.
In case you did not know, they work by a puff of air operating the mechanism in the box at one end of the tubing, when a vehicle passes over the tubes. Puff.....................Puff, will give you one reading of speed, Puff....Puff, will give you another. They also record the number of vehicles which go over them. Anything else you are not sure of, just ask.