The Oberau Tunnel is less than two years old. He celebrates his birthday in May. But it needs to be retrofitted at great expense. Mayor Peter Imminger believes this is the only right path for his community. So that the cars from Oberau really stay outside.
Oberau
– The Oberau Tunnel was intended to free the locals from traffic jams, noise and exhaust fumes. He does. Since May 27, 2022, traffic has been rolling past the town through the two tubes. Unless the tunnel is being maintained. Like a week ago. Experts spent five days examining the operating technology and checking the safety programs - and the cars returned to Oberau. Because they are not allowed to drive through a tube in oncoming traffic.
Two years ago, Mayor Peter Imminger (CSU) made it clear to the Tagblatt: “It doesn't work that way.” A bypass is being built for 228 million euros and traffic is then redirected through the town. “That would be a prank.” The Weilheim State Building Authority promised to do everything it could to solve this problem. It seems those responsible are keeping their word. Which is why the town hall boss appeared extremely relaxed during this most recent week of maintenance. “Me, that’s just the way it is right now.” Probably until 2025.
Search for a solution dragged on
The State Building Authority actually wanted to have found a solution by the first maintenance in spring 2023, or at the latest by the second in autumn. The search for it dragged on. But now all the preparatory work should be done. Among other things, a report was drawn up in Switzerland that examined whether the Oberau Tunnel can generally be operated in two-way traffic and, if so, under what conditions. The biggest challenge was the flow behavior of the smoke gases in the event of a fire, explains department head Lukas Schulte. Finally, in an emergency, the ventilation system must automatically recognize in which direction it needs to blow the smoke. This can apparently be solved – through “some operational, structural and software-based changes”. An engineering office is currently preparing the tender and Schulte wants to place the order for the conversion as soon as possible. This is expected to last six months, followed by a one-week test phase.
The question arises: Why wasn't this taken into account from the start? It wasn't intentional, explains Schulte simply. “The federal government’s requirements did not include the suitability of the Oberau tunnel for two-way traffic at the time of construction.”
Farchanter variant would have been too expensive
If the planners at the State Building Authority had had their way, they would have built another tunnel anyway. One like in Farchant. One with a false ceiling, huge fans, automatic ceiling flaps and revolving doors that can be used to precisely extract smoke in the event of a fire. With such a system, oncoming traffic can be controlled without any problems. If one tube is blocked, cars roll through the other in both directions. For Oberau, however, the government rejected this solution many years ago - it was too expensive. This variant would have cost at least 30 million euros more than the 24 ceiling fans, an expert told the Tagblatt in May 2022.
In comparison, the 970,000 euros seem like nice play money. Schulte estimates that this is how much the conversion will cost. Specifically, the ventilation is given the option of video detection, additional flow meters are installed, expanded traffic programs are created and the control of the jet fans is reprogrammed. The adjustment would have been significantly more expensive if the team led by project manager Christian Schauer had not been so proactive in building. Some precautions have already been taken for oncoming traffic. For example, the information signs – such as a red X for a closed lane – can be switched from both sides. But that is not enough for a two-way traffic permit.
Schulte doesn't know when the renovation will start. Only that it should be completed in 2025. There are likely to be disruptions during the work. The cars will probably roll through Oberau again. In this case, Mayor Imminger will easily get over it.