Marburg plans to convert its city bus lines 7 and 27 to battery-powered trolleybuses (BOB) by 2030 – an intelligent combination of overhead lines and batteries designed to ensure emission-free urban transport. The total cost of infrastructure and buses is estimated at around €45 million net. In January 2021, Marburg received federal funding of around €1.52 million for planning services. On 22 August 2025, the Giessen Regional Council issued the planning approval decision, meaning the project is now ready for construction. However, the financing of the overall project is still open, which is why the city is now hoping for new funding commitments from the federal ‘Infrastructure Special Fund’ programme.
Topographical challenge mastered
The routes with a total length of 10 km run from the low-lying city centre up to the university and hospital on the Lahnberge hills – some as high as 370 metres above sea level. Pure battery buses would be unsuitable for this, as they would require oversized batteries for such gradients and ranges. The use of overhead lines for the ascent plus batteries for free driving is therefore more efficient and cost-effective.
Technology and capacity
The vehicles are to be procured as 24-metre-long double-articulated buses. They are purely electric, drawing energy from overhead lines while driving and charging their batteries at the same time. Braking energy is also recovered. During rush hour, the initial transport capacity is expected to be up to 550 passengers per hour, with the prospect of increasing this to as many as 700.
Expansion and infrastructure
The overhead line infrastructure will only be installed on particularly relevant sections of the route. Around 900 catenary and crossarm masts are planned at intervals of around 25 metres, for example along Neue Kasseler Straße, Ginseldorfer Weg, Panoramastraße and on the Lahnbergen hills. Several rectifier substations are also required to convert medium voltage into 600–900 V direct current.
Citizen participation as a factor for success
Since May 2023, the city has been actively informing its citizens about the project. Around 120 people attended a kick-off event in May, and around 60 attended another in September. At the same time, an online dialogue is taking place via the ‘MarburgMachtMit’ platform. The aim is to ensure acceptance and transparency during the planning approval process.
Facts at a glance
- Objective: Electrification of lines 7 and 27 by 2030
- Technology: Combination of overhead lines (gradients, power supply) and batteries (flexible sections)
- Buses: Double-articulated buses with a length of 24 metres, up to 700 passengers per hour during peak times.
- Infrastructure: Around 900 masts, cross-arms, rectifier substations
- Cost: Approximately 45 million euros net
- Funding for the planning phase: €1.52 million from the federal government
- Approval: Planning approval decision in August 2025, financing still uncertain
