According to the regional authorities, there are several reasons why the planned timetable can no longer be met: Immediately after the start of construction in May 2019, pollutants were discovered on the rear bridge in the direction of Altenberg. According to press spokesman Sebastian Bauer, the sealing of the structure was contaminated with polycyclic aromatic hydrocarbons and had to be disposed of as "waste requiring special monitoring". A further delay occurred because the heights of the road surface on the bridges were irregular. As a result and according to their own statement, the NRW road authority had to develop a new concept for demolition. Consequently, the sealing of the bridges and the asphalt still remaining after milling were removed by means of a mobile excavator and were separated for disposal.

Engineers discovered an additional problem with both structures at the so-called bridge caps, i.e. the edges that cannot be driven over. These were “underrun”, i.e. their stability was at risk. The concrete in the lower area of the safety kerbs had also been severely damaged on both bridges.

All these defects have resulted in further unforeseen construction work. “This was not evident prior to the execution of the work,” said Sebastian Bauer upon request. Some construction work had also not been completed due to the bad weather and low temperatures in November and December 2019.

The upgrading is now scheduled to be completed in the course of this year. Whether the current time plan can be kept to, however, will again depend on the weather, according to the NRW roads authority. In order to seal the bridges with a so-called bituminous sheeting, a soil and air temperature of five degrees Celsius as well as dry weather is required. If the roadway is soaked, it has to be dried with great effort before the construction work begins. “Work will be resumed when the weather is forecast to be good in the longer term,” Bauer said.

If everything goes according to plan, the current construction phase in the driving direction of Bonn should be finally completed in February. This will be followed by two further construction phases in the direction of Altenkirchen. During this phase, there will no longer be any need for diversions and all junctions will be open to traffic again. The total costs for the upgrading of the two bridges amount to 3.4 million euros. Among other things, the NRW roads authority will renew the road surfaces, replace parts subject to wear at the road junctions and renew parts of the noise protection system.

(Original text; General Anzeiger, translation John Chandler)