Operational Experience with Temporary Hard Shoulder Running in Germany

Hard shoulder running is an effective measure to increase the capacity of frequently congested freeway sections during peak hours. This paper reports on the experience with temporary (dynamic) hard shoulder running on two major freeways in the German federal state of Hesse. The basic design principles and operational aspects related to hard shoulder running are covered. On the basis of loop detector data, the effects of temporary hard shoulder running on freeway capacity and traffic flow characteristics were analyzed. Results showed that the capacity of a three-lane carriageway was increased by 20% to 25% if the hard shoulder was used as an additional lane during peak hours. The acceptance of hard shoulder running is considerably high among truck drivers.