The existing combined sewer runs very deep underground in Adenauerallee. Instead of repairing the gullies and reconnecting them individually to the sewer, the city wants to lay so-called gully collection pipes at a shallower depth. These will be connected to the sewer in some places, but no longer - as was previously the case - to each individual gully. While trenchless renovation with so-called liners is possible in large areas, in some places, such as near the Juridicum, a new open trench construction is required.

For reasons of cost efficiency and to reduce the impact on traffic, a new carriageway will be installed across the entire width immediately afterwards.

The work will be carried out in sections (it has not yet been determined how traffic will be routed during the construction work) and is scheduled to begin after the 2023 summer vacations in order to keep the B9 free as one of the main connecting axes in the city during the full closure of the A59 during the summer vacations.

Speaking of width: as up to 1,600 vehicles per hour use Adenauerallee in both directions at peak times, the current guidelines stipulate that a safe cycling facility must be created when the road is built. This means a two-metre-wide cycle lane with a 50-centimetre-wide safety strip. With two additional adjacent motor vehicle lanes at least 5.50 meters wide, a width of eight meters would be required in each direction. However, this width is not available on Adenauerallee. With this in mind, the city is planning to set up the protected bike lane and a lane for motor vehicle traffic with additional turning lanes in the intersection areas.

Adenauerallee forms an important gap in the north-south axis for bicycle traffic between the Sandkaule/Belderberg area in the north and Bundeskanzlerplatz in the south. It is the direct axis from the city center towards the Museum Mile and the Federal Quarter. And via this route - parallel to the routes on the banks of the Rhine and along Kaiserstraße - numerous important destinations (federal authorities, university facilities, university library, employers and doctors' surgeries) can be reached directly by bike.

In the updated cycling network, which is currently being discussed by the committees, Adenauerallee is designated as a main route for the reasons mentioned above. The installation of safe cycling facilities is a particular priority on main routes.

Traffic counts have shown that there are significantly fewer motor vehicles on the north-south axis compared to the east-west axis with Oxfordstraße, where environmental lanes and cycle lanes have already been successfully installed, but more cyclists. East-west axis: around 30,000 motor vehicles and 2,100 cyclists per day; north-south axis: around 21,000 motor vehicles and around 3,500 cyclists per day. In combination with the bottleneck at Koblenzer Tor, where motor vehicle traffic is currently already routed in one lane, the city administration believes that motor vehicle traffic on Adenauerallee can continue to be routed in one lane plus turning lanes.

There are currently 119 parking spaces for cars along Adenauerallee, including three disabled parking spaces. In the new plan, 69 parking spaces will be retained during the day and 24 parking spaces are planned as delivery zones, which will be made available to residents at night. During the day, the spaces will be available for tradesmen, parcel services and other suppliers.
From the evening and at night, there will be a total of 93 parking spaces (including five disabled spaces) for residents. Additional bicycle parking facilities will also be created in four areas.

In most cases, the number of parking spaces will be reduced by converting angled parking spaces into longitudinal parking spaces or eliminating parking space on the roadway. This is intended to avoid dangerous situations when parking in or out of spaces where the view of moving traffic is severely restricted - especially in angled parking spaces.

Once a decision has been made in the committees, residents will be informed about the measure by means of a mailing. Residents, businesses and other interested parties will be offered an appointment on site with representatives of the city administration to explain the plans as part of a tour and clarify any unanswered questions.

The measure is estimated to cost around 3.65 million euros in total. Of this, around two million euros will be spent on the road surface renovation, around 300,000.00 euros on adapting the traffic lights and around 1.35 million euros on markings, signage, spot red markings and the Protected Bike Lane. Added to this are the costs for the sewer renovation, which cannot yet be reliably estimated.

The city administration's draft resolution is published  here (opens in a new tab).