Interference with traffic flow primarily during the night
For the work to be carried out on the A8, one of the specified requirements is that the impacts on road users and the population in the Bernese Oberland region must be kept to a minimum. However, for certain activities the closure of the involved stretch is unavoidable, and since the traffic volume is much lower at night than during the day, these activities are to be carried out during the night.
The stretch between Interlaken-Ost and Brienz was opened to traffic in 1988. It provides a connection between the Haslital/Lake Brienz region and Interlaken and its surroundings. This stretch is part of a heavily frequented route during the peak tourism season in the summer.
The work schedule has been designed to minimise interference with traffic flow. Due to the fact that it passes through a number of villages, the diversion via the right-hand shore of Lake Brienz is only suitable for use during periods when there is little traffic. In view of this, practically all tasks that call for the closure of the stretch will be carried out at night. During the day, the stretch of the A8 between Interlaken-Ost and Brienz will remain open to traffic, with two lanes available along the entire stretch.
At night, the traffic volume is much lower than during the day. More than 90 percent of vehicles using this stretch do so between 6 a.m. and 8 p.m., and this means they will not have to deviate from their accustomed route. Thanks to night work, the level of disturbance for local residents along the alternative route can be kept very low. After midnight, the traffic volume on this route is normally only around 20 to 30 vehicles per hour.
During the construction of the emergency galleries, very few lane closures will be required at night. For the total renovation that is to be initiated in 2020, however, lane closures at night will be necessary along the entire stretch.