Bonn and Troisdorf will have to wait many more years for the planned full-scale operation of the airport S-Bahn line. Deutsche Bahn does not expect the crucial bridge—a grade-separation structure intended to route trains onto the airport line without crossing other tracks—to be completed until the 2040s; the structure was missing from the original project plan. Consequently, service will launch on December 13, 2026, using only an interim operating plan. Passengers will benefit from more connections, though a reliable 20-minute service frequency to Cologne will not yet be available. At the same time, Bonn plans to discontinue the direct SB60 airport bus.
Airport S-Bahn Line Requires Additional Bridge in Troisdorf
Planning for the S13 line has been underway since 1997, while major construction work began in November 2016. Deutsche Bahn is expanding a section of existing track—spanning less than 15 kilometers—between Troisdorf and Bonn-Oberkassel. In addition, new tracks, stations, bridges, signal boxes, and noise barriers are being built. By the end of 2026, around 80 percent of the expanded line as far as Bonn-Beuel is expected to be operational. Deutsche Bahn will reach this section two years earlier than previously announced.
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The missing grade-separation structure is located at the Troisdorf railway junction, where trains from Bonn, the Sieg Valley, Cologne, and the airport converge. Without the bridge, however, certain tracks must continue to cross at the same level. Consequently, delayed trains can block other connections. DB project manager Jens Sülwold now considers an opening before the 2040s unlikely; previously, the second half of the 2030s had been considered a possible timeframe.
Interim concept replaces promised target service
Starting in December 2026, the new tracks will initially be used for mixed operations. An S27 service will therefore shuttle hourly between Troisdorf and Bonn-Beuel. Additionally, one S12 train per hour will run to Bonn-Beuel instead of the Sieg Valley. The RB27 will also serve all the new stops. Stakeholders are still evaluating an additional stop for the RE8 in Bonn-Vilich.
At a later stage, the S13 is scheduled to run twice an hour from Bonn-Beuel via the airport to Cologne. However, this level of service requires the region to have sufficient rolling stock and available track capacity. The ultimate 20-minute service frequency also necessitates the expansion of the Cologne S-Bahn hub, alongside the construction of the new bridge in Troisdorf. As a result, despite the new infrastructure, the airport S-Bahn service will fall short of the original goal for years to come.
Direct airport bus service still set to be discontinued
The SB60 bus line currently provides a direct link between Bonn Central Station and Cologne/Bonn Airport without requiring a transfer. It runs every 30 minutes and serves key areas of the city center. Bonn plans to discontinue the service when the timetable changes on December 13, 2026, citing the new rail connections via Bonn-Beuel and Bonn-Vilich. However, travelers from the city center will then have to cross the Rhine and transfer.
The expansion project also remains incomplete south of Bonn-Beuel. Current plans indicate that major construction work extending to Bonn-Oberkassel will not begin until after 2030. In the meantime, the railway is utilizing the five-month closure of the right-bank Rhine line to carry out extensive construction work. While new tracks and stops will improve service, the crucial separation of traffic flows for the airport S-Bahn line is not expected to materialize until more than 40 years after planning began.
Author: Blackout News
Sources: RTL (23.07.26) – Airliners (21.07.26) – Bahnknoten Köln (14.07.26)