Purpose : The focus of this paper is to enhance our observation and knowledge of interurban road freight transport. It explores some possibilities for improving roadside freight surveys, usually used to gather origin-destination data. Methodology : To achieve this, new questions are added to a standard roadside survey form, and the enhanced survey form is tested through two surveys. The new questions relate to currently unobserved variables: the vehicle volume occupied by freight; the method of organisation (double crew, relays) used by the carriers; the existence of speci c logistical imperatives; and drivers' compulsory breaks. Results : The questions on volume constraint and carrier organisation prove to be the most informative. These two questions are thus two promising areas for improvement in roadside freight surveys. The questions about speci c logistical imperatives and driver breaks prove less fruitful. Conclusion : The paper concludes that it is possible, through minor modi cations in data collection protocols, to signi cantly enhance observation quality in road freight transport activity.