Effects of hard shoulder lanes configuration on driver’s behaviour

Nowadays, reassignments of hard shoulders into traffic lanes are spreading across Europe. This traffic management measure allows to respond to the growing saturation of high-capacity roads.In Switzerland, the first stretch to be equipped in such a way was opened in 2010. This article aims to highlight the impact of specific road marking and the configuration of the freeway section or stretch on the users’ behaviour. A presentation of the active hard shoulder lane system and of its geometric specificities are approached in detail. The users’ perception of the system, the lateral position of vehicles across the different lanes and the behaviour of motorists in the motorway entrance and exit areas were studied. It was thus underlined that the geometric specificities of the hard shoulder lane could hinder some users who were therefore reluctant to use that lane. This is one of the reasons for the inferior rate of use of the hard shoulder lane as compared to that of the right lane on a conventional three lane motorway. The final destination of motorists also plays an important role in the choice to use that lane, especially in the entry and exit zones of the system. The lateral position of vehicles in the hard shoulder lane is also influence by its marking peculiarities, with a more centred positions for vehicles in this lane than in other lanes of the stretch.