From the user’s (drivers) point of view, a road is a unique linear infrastructure although it is clear for a driver that such a linear infrastructure consists of open terrain (open roads) and occasionally closed environment (tunnels). Since the two environments present different safety issues, the related analyses are usually conducted on the field by different experts; those conclusions are sometimes not well interlinked and harmonised, leading to safety gaps particularly, but not only, in the transition areas. Joint safety analyses conducted in the same time by a group of road safety and tunnel safety experts can fill such a gap and increase the safety level of the whole infrastructure. During the year 2016, an international group of road safety experts and tunnel experts visited five road sections with open roads and tunnel in Europe and performed joint safety analyses together with the infrastructure managers. Such analyses were conducted according to a predefined experimental procedure to check the effectiveness of the joint analyses with respect to the usual ones. The key results are that joint safety operations in tunnels and open roads are possible and extremely useful: their cost can be very low when well planned.
Part of the book: Highway Engineering