In the 1990s, public transport rarely brought trolleybuses to mind. The narrative was one of retreat: many cities worldwide shut down their trolleybus networks, replaced by diesel buses – more flexible, cheaper, ostensibly more modern. Switzerland held its ground. And today it is clear: it was the right decision.

The trolleybus is experiencing a remarkable renaissance – not only in Switzerland, but worldwide. What lies behind it – and what does this mean for overhead line infrastructure in Swiss cities?

Switzerland as a European Exception

While other countries dismantled their trolleybus networks, cities such as Lausanne, Lucerne, Berne, Zurich and Geneva consistently continued to operate their trolleybus lines. The reasons were pragmatic: the infrastructure was in place, operating costs were predictable, and Swiss engineering tradition valued what had proven itself.

Today, this continuity is a strategic advantage. The existing overhead line networks form the backbone of modern, emission-free urban mobility – without the effort of complete reconstruction.

Why the Trolleybus is More Attractive Today Than Ever

1. Zero Local Emissions – Without Compromise

Battery buses have made progress, but continue to struggle with range, charging times and battery degradation in cold weather. The trolleybus draws its power directly from the overhead line network – continuously, reliably, independent of battery capacity. In cities with steep gradients (Lausanne, Lucerne), this is not a minor detail but a decisive operational advantage.

2. Hybridisation as a Game Changer

Modern trolleybuses no longer operate exclusively under the wire. Thanks to auxiliary batteries or supercapacitors, they can travel short distances without overhead lines – for example, in narrow old-town streets or around construction site diversions. This makes route planning considerably more flexible and reduces infrastructure costs in difficult sections.

3. Energy Recovery in Urban Operation

When braking, the trolleybus feeds energy back into the network – an effect that carries considerable weight precisely in the stop-and-go operation of urban lines. This recuperation makes the trolleybus more efficient than alternatives that dissipate braking energy as heat.

4. Long Infrastructure Lifespan

A well-maintained overhead line system has a service life of 30 to 40 years. Overhead lines are therefore one of the most durable investments in urban transport – provided that planning, execution and maintenance comply with the relevant standards (EN 50119, VÖV guidelines).

What This Means for Overhead Line Infrastructure

The flip side of continuity: many Swiss overhead line systems date from the 1970s and 1980s. They have reached or already passed their peak. At the same time, demand is growing – new lines, higher frequencies, heavier vehicles, more modern feeder points.

This creates a considerable renewal requirement that will materialise in concrete projects in the coming years:

For specialised engineering firms such as BayTech GmbH, this means: the project pipeline in this segment is structurally full – not driven by economic cycles, but by the simple physical ageing process of the infrastructure.

Examples from Practice

Lausanne has invested heavily in its trolleybus system in recent years and today operates one of the most modern trolleybus fleets in Europe.

Lucerne continuously rehabilitates sections of its overhead line systems and is evaluating extensions in connection with urban development.

Geneva operates one of Switzerland's largest trolleybus networks and is working on the modernisation of its feeder infrastructure.

These projects are not isolated cases – they are symptomatic of the renewal cycle that will shape the industry over the next 10 to 15 years.

Conclusion: The Trolleybus Is Not Nostalgia

Anyone who regards the trolleybus as a legacy technology is mistaken. It is a mature, emission-free technology that, in combination with modern hybridisation and digital planning, fits very well into 21st-century urban mobility – and in Switzerland has already demonstrated in practice what is still being debated elsewhere.

The real challenge lies not in the technology, but in the infrastructure: existing overhead line networks must be expertly rehabilitated, extended and documented. This requires specialist knowledge that is scarce in the industry – and correspondingly in demand.