Verkehrssicherheits- und Verkehrsablaufuntersuchungen in Arbeitsstellen längerer Dauer auf Autobahnen in Deutschland

  • Traffic safety and traffic flow analysis of long-term roadconstruction sites on German motorways

Sümmermann, Andreas; Steinauer, Bernhard (Thesis advisor)

Aachen : Publikationsserver der RWTH Aachen University (2012)
Dissertation / PhD Thesis

Aachen, Techn. Hochsch., Diss., 2012


In the coming years the maintenance costs for the German motorway network will continue to rise. The vast majority of the German motorways were opened to traffic between 1965 and 1985, which means that these sections of road are increasingly becoming in need of renovation. The simultaneous increase in traffic load and particularly the high proportion of heavy traffic are causing considerable damage to the road surface. This leads to an increased need for both short-term and long-term construction sites. In Germany the traffic routing forms 3+1 and 4+0 are mainly used in the area of long-term construction sites. These forms of traffic routing are in direct competition with each other as they can be used under very similar boundary conditions (cross-sectional widths, traffic load etc.). In the context of the scientific tests both forms of traffic routing were subjected to a safety and a traffic flow analysis. The evaluation of over 6,500 traffic accidents in 269 construction sites yielded the results that 3+1 construction sites show an average of 10% lower general accident risk than 4+0 construction sites. Furthermore in an accident with personal injury considerably more road users are injured or killed in 4+0 construction sites. Narrow inner areas of construction sites may at first glance seem safer than wider 4+0 construction sites, the effects of narrow road lanes however on the capacity and the more massive congestion situations involved are to be evaluated negatively in particular with regard to the hazard of traffic jams on road safety. Neither does the introduction of "staggered traffic" in combination with a general ban on overtaking on narrow lanes promise a long-term solution to efficiency problems. The efficiency still remains restricted in contrast to wider lanes and a significant reduction in traffic jams cannot be expected. The evaluations of the traffic flow tests in 20 empirically tested construction sites reveal that the capacities in 3+1 construction sites are up to 12% higher than the capacities of 4+0 construction sites. In particular with heavy traffic proportions of over 15%, 3+1 traffic routings show advantages with regard to efficiency. The evaluation of the above-mentioned findings from the safety assessments and traffic tests leads to the conclusion that 3+1 construction sites must be recommended and 4+0 construction sites preferred.