Add to ORKGThe objective of this experimental study is to get relationships of general validity for the prediction, in phase of project, of the speeds that will be indeed practiced on the infrastructure. The experimental investigation, object of the present paper, has been conducted employing traffic counters, able to record, for every vehicular passage in both senses: length, instant speed and direction of the vehicle. The plan of survey has been elaborated to satisfy different objectives of search (speed in free flow conditions, in entry and in gone out of the intersections, in rural to urban transition, etc.) and it has been applied to some belonging roads to the network of the Province of Salerno. The measures have been performed holding under obs...