Road construction site management system 11 comprises field element 3 and a central processor. The field element acquires own position (e.g. from GPS 5, Fig.2) and/or traffic data (e.g. speed, volume or identity detected by traffic sensor 5, Fig.2). It receives control data (e.g. specifying data collection times or intervals) from the central processor and transmits traffic data and/or own position data to it via communication means (6, 9, Fig.2). It may include display and input means (7, 8, fig.2) such that an operator can notify the central processor that the field element is in place. Central processing means (4, Fig.2) may update and output information determined from the position and/or traffic data such as travel delays due to the road works or a recommended diversion route.
