Under the Roof

A steel cathedral for sustainable mobility

Nollendorfplatz Bülowstraße


Between the embassy district and arabic supermarkets lies a historically LGBT neighborhood, a community of shared apartments from the late 1960s, streets where individuals solicit prostitutes, and an array of hip galleries. Almost no other Berlin neighborhood is as heterogeneous as the streets surrounding the subway stations of Nollendorfplatz and Bülowstraße. The Radbahn will likewise reflect the diversity of this neighborhood, as we have designed a mobility hub at Nollendorfplatz to offer added value to all traffic users.

The Route

Shortly before Nollendorfplatz, the U2 subway line emerges from the ground and runs along the elevated rail viaduct. The Radbahn flows past Wittenbergplatz with both lanes north of the U-Bahn tunnel exit, and continues along the northern side of Nollendorfplatz. From here on, the rail viaduct protects cyclists. Part of the viaduct retains the decorative charm of the original 1898 construction. The railway station at Bülowstraße is an ideal location for the Radbahn, as the ample space provided allows two bike lanes to pass through the middle of the street.

Ramp towards Nollendorfplatz, around 1902 Arbeitsgemeinschaft Berliner U-Bahn e.V: Construction of the Berlin U-Bahn, page 10, BVG, Berlin 2001 / unknown photographer

The tunnel entrance where the elevated railway begins marks the border between the wealthier neighborhood of Charlottenburg (still a self-governing city in 1920) and the working class districts of Schöneberg and Kreuzberg.

The Character of Nollendorfplatz

Nollendorfplatz was originally designed as a decorative square (known as Schmuckplätze in German) during the German Imperial Era (1871–1918) and contained a lot of greenery and water fountains. Its original character was lost due to significant damage during the Second World War and the subsequent conversion of the plaza in the early 1970s. Although it is somewhat smaller today, Nollendorfplatz is a major transportation junction featuring four subway lines and seven bus routes.

We see great potential for Nollendorfplatz, as it could act as a new mobility hub. The existing architecture and infrastructure are ideal for a new interface between public transport, pedestrians, cyclists and e-mobility options. We have focused particularly on cycling and car-sharing models, as well as new possibilities for advanced multimodality.

Lush park around the Nollendorfplatz Photographer: Max Missmann, Berlin, 1909. Inv.-Nr.: unknown © Stiftung Stadtmuseum Berlin

The decorative square was named after the Prussians’ victorious battle in Nollendorf (now part of the Czech Republic). Nollendorfplatz was affected by the Hobrecht land-usage plan and its construction was overseen by Peter Joseph Lenné, the Director General of the Royal Prussian Palaces and Parks.

Fountain on Nollendorfplatz Photography: Max Missmann, Berlin, 1904. Inv.-Nr. : IV 67/513 V © Stiftung Stadtmuseum Berlin. Reproduction: Michael Setzpfandt, Berlin

The functional U1 viaduct was made more attractive at the beginning of the 20th century with the installation of a romantic fountain and lawns. Then as now, the goal was to create a people-friendly city oriented towards achieving spaces for socialization, recreation and relaxation.

Nollendorfplatz Today

Today the square is dominated by the subway station and two wide roads, one on each side of the elevated railway. The north-south route has three-lanes.

Proposal for Nollendorfplatz

The low amount of traffic at Nollendorfplatz makes it possible to reduce the size of the north-south axis. A mobility hub for bicycles, e-bikes and e-scooters could be created underneath the generously dimensioned covered area east of the station building. To the south of the square, e-cars could be available for hire. Kiosks and recreational infrastructure could be added around the fountain in the western section.

Alternative Proposal

Old plans and photos show a large, urban Nollendorfplatz with lots of trees that is only bisected by footpaths. The square’s former character is worth restoring in a way that corresponds with the needs of modern cities. We envisage a lively and beautiful plaza that provides quality public space and stands for new urban mobility.

Mobility Hubs along the Radbahn

The Radbahn affords several opportunities to demonstrate intermodal mobility (via mobility hubs) along its route, as our proposal connects many modes of transport. Bicycle, foot and road traffic exist along the entire route and the existing and planned railway stations are ideal locations for our hubs. Every station has the potential to become an intermodal transfer platform and we believe the following six stations present particularly exciting opportunities:

  • Bahnhof Zoologischer Garten (regional, S-Bahn, U2, U9 and several bus lines)
  • U-Bahnhof Nollendorfplatz (U1, U2, U3, U4 and several bus lines)
  • U-Bahnhof / S-Bahnhof Gleisdreieck – (S21 currently being planned, U1, U2)
  • U-Bahnhof Hallesches Tor (U1, U6 and bus lines)
  • U-Bahnhof Kottbusser Tor (U1, U8)
  • S-Bahnhof Warschauer Straße (S-Bahn, U1, Tram M10)
    Depending on the available space and the municipal mobility concept, we will be able to offer bike parking lots (including lockable boxes for expensive bicycles and cargo bikes), charging stations for e-car and e-bike sharing, normal rental bicycles, as well as pick-up stations for mobility service providers and DIY repair stations. Of course, this range of mobility should not be monofunctional, as people often want to take a break as they travel from A to B. Our concept includes places to eat, seating and greenery along the Radbahn route.

Mobility Hub Nollendorfplatz

Inspired by its charming history, we see Nollendorfplatz as the perfect location for a mobility hub: it already has three subway lines, several bus connections, a central urban location, as well as enough space for recreational infrastructure and a transport exchange (from bike to bus, train, car, etc.).

In addition to its intermodal functionality, we also view the Radbahn as a tool for disseminating information. Car owners are generally predisposed towards continuing to use their own personal vehicles. The Radbahn will exhibit suitable sharing models and provide car owners with an alternative to their current mobility usage. This is particularly important, as the first step towards changing a habit is often the most difficult.

Mobility Hub Nollendorfplatz

“This project is an exceptional example of how new potential is recognized in existing yet untapped resources in urban areas and integrated into an eco-friendly concept. The ‘Radbahn’ has initiated a discourse about the attractiveness of cycling in city traffic and this route in Berlin is particularly in need of attention.” Prof. Dr. honoris causa Erik Spiekermann, designer of the Berlin logo and developer of the BVG public transport signage system after the fall of the Berlin Wall.

The access road to the parking spaces would become the Radbahn path. Parking spaces could be maintained during the transitional phase, but would ultimately be relocated to the road along the viaduct, as shown in the image below.

Under the Railway: Construction from 1898

On Bülowstraße between Nollendorfplatz and the park at Gleisdreieck, the structure of the viaduct is particularly wide and largely unaltered from the design that architect Alfred Grenander devised at the end of the 19th century. All that is required is good lighting for visibility and safety, and green areas to separate cyclists from motorized traffic.

Through the Station

Shortly before the Bülowstraße subway station, the Radbahn crosses over Potsdamer Strasse, which is part of the B1 federal highway. On the following pages, we will analyze this crossing as a case study with regard to the safety of road users, especially cyclists and pedestrians. This will be followed by a discussion of all the intersections and station types that the Radbahn crosses.

Detail of the Intersection at the Bülowstraße Station

Intersection Bülowstraße and Potsdamer Strasse – Traffic Light Strategy
The traffic lights at the major Bülowstraße/Potsdamer Strasse intersection generally feature two-phase systems (the east-west direction has precedence) for reasons of performance. If the stop lines where the cars have to wait were moved back slightly, it would be possible to integrate the Radbahn into the middle of the road without interfering with the existing system.

At peak times when there is a high volume of traffic, special traffic light sequences for road users turning left could be introduced (this approach is used when there is a tram line in the middle lane, for example). At Bülowstraße, there is a lane for left-hand turns. The Radbahn could bypass this lane together with other vehicles driving straight ahead, thereby protecting cyclists from cars turning left.

90% of right-turn accidents between cyclists and drivers are caused by the drivers, according to a study by the German Insurers Accident Research (UDV)*

*Unfallforschung der Versicherer (UDV) (2013): Unfälle zwischen abbiegenden Kfz und Radfahrern. Unfallforschung kommunal Nr. 16. https://udv.de/de/publikationen/unfallforschung-kommunal/unfaelle-zwischen-abbiegenden-kfz-und-radfahrernradfahrern)

The Radbahn crosses over Potsdamer Strasse and runs underneath the Bülowstraße subway station.