The evidence that got a school its crossing

Alba is the head of a primary school in Valencia, four hundred pupils, three gates on a busy road. Cars race past at pick up time. She had asked the council for a crossing three times. Each time the answer was the same: show us the numbers. She had none, only a near miss in March. With xMap Flows, Alba built Kestrel. Every school day at a quarter to three, at each of the three gates, Kestrel measures how fast the traffic moves, works out how far over the limit it is, and adds a row to her evidence sheet. After one term, Kestrel’s sheet showed cars passing the main gate at almost twice the limit on most afternoons. Alba sent it to the council in May. The crossing was painted in September. Alba stopped asking for a crossing. She sent the proof instead.

The story in words