Abstract
The present system of operation on the motorway comprises variable traffic signs at six locations between Paris and Le Bourget to give information on carriageway conditions or traffic ahead by means of luminous messages. The object of the survey described was twofold (1) to inquire about the reactions of drivers confronted with those signs, and (2) to use the data collected to inform the users of current studies and realisations for improving safety, traffic flow in peak hour and during incidents on the motorway.