Bridges get graded

Improvement needed for bridges in Bonn and the region

Über diese Brücke an der Villemombler Straße verläuft die Autobahn A565. Das Bauwerk muss dringend erneuert werden.

The Autobahn A565 goes over this bridge on Villemombler Straße. (archive photo)

Bonn/Region. The Federal Highway Research Institute (Bast) in Germany has examined the condition of bridges throughout the country. Here you can read what grades have been given to bridges in Bonn and the region.

Nearly four months ago in Genoa, 43 people lost their lives when the four-lane Morandi Bridge collapsed.  The tragedy on August 14 also resulted in more than 650 people losing their homes.   In an effort to prevent such a tragedy from happening in Germany, the Federal Highway Research Institute (Bast) regularly checks the condition of the bridges in Germany.

The most recent data, published in November, offer a mixed assessment of the buildings in Bonn and the Rhein-Sieg district - only a few of the 346 bridges (147 in Bonn, 199 in Rhine-Sieg) or sections of bridges meet the highest standards. In its analysis, Bast assigns grades from 1.0 to 4.0, depending on their condition, with 1.0 to 1.4 being very good, 1.5 to 1.9 good, 2.0 to 2.4 satisfactory, 2.5 to 2.9  sufficient, 3.0 to 3.4 for insufficient and 3.5 to 4.0 for an unsatisfactory condition.

The subsequent maintenance of the bridges is then planned on the basis of the grades awarded. "Depending on the degree of urgency and the type and extent of the deficiencies identified during the building inspection, they will be remedied immediately or in the intermediate term within the framework of the maintenance schedule, which will lead to an improvement in the condition outside of the inspection cycle," Bast explains.

Only two bridges - over the Autobahn 555 at Oppelner Straße and the underpass of the B56 at Mühlenbach received the grade "very good". More worrying is the bridge over the A565 on Kölnstraße in Bonn-Auerberg. Both the taxi lane and the driving lane were not rated as satisfactory. 

The chart shows that something will have to happen sooner or later not only on Kölnstraße. According to Bast, there is a higher need for corrective action in the case of bridges that receive a grade of 3.0 or worse, especially those with a grade of 3.5 or lower. However, Bast points out that such a rating can also be due to a lack of bars in the railing, it doesn’t mean such a bridge is close to collapsing.

In unsatisfactory condition is the overpass at the Siefenbach in Lohmar. With a grade of 3.5,  it received the lowest marks in Bonn and the region. But there was also much better news in Lohmar: The overpass above the Auelbach river did very well and in no section did it rate worse than satisfactory.

Why are some of the bridges throughout Germany and here in our region partly in poor condition?  In response to a GA inquiry, the NRW Ministry of Transport largely attributes one reason for this: The bridges were simply not designed for the stresses to which they are now exposed on a daily basis.

"Not only when it comes to federal highways and state roads, but also in the domain of municipal roads, the bridge infrastructure in many parts of Germany has reached its limits earlier than expected," says Leonie Molls from the press office of Transport Minister Hendrik Wüst. In the coming years, the state government will invest "record sums" in the maintenance, modernization and expansion of roads and bridges.

At the latest since this summer, it has become clear that there is work to do on the bridges  in Bonn and the region. From 2028, the north bridge in Bonn is to be replaced by a new construction. The evaluation from Bast shows that construction work and repairs are also likely to be carried out on many smaller structures in the foreseeable future.

The complete report for Germany can be found here: https://www.bast.de/BASt_2017/DE/Ingenieurbau/Statistik/statistik-node.html

Orig. text: Laszlo Scheuch, Translation: Carol Kloeppel)