RegioJet a.s.

Updated: August 2026 – Anyone who follows a train right across Czechia eventually runs into a peculiarity that many neighbouring countries don’t share in this form: the country runs on two different electrification systems, and the boundary between them sits in the middle of the network. RegioJet a.s. is one of the passenger operators whose trains can run across both systems – and a good excuse to take a thorough look at the subject of electrification systems.

What is RegioJet a.s.?

RegioJet a.s. is a Czech company in rail passenger services operating under the brand RegioJet. The company name is made up of two internationally understandable elements: Regio points to region, Jet to speed. The suffix a.s. stands for akciová společnost, i.e. the Czech joint-stock company.

What the name does not say: which connections are served, with which vehicles and on what scale. Such details change constantly. What stays constant, though, is the question every spotter must answer in the field – and in Czechia there’s one that rarely comes up elsewhere: which power supply is the train actually running on here?

One country, two electrification systems

The northern part of the Czech network is electrified with 3 kV DC, the southern part with 25 kV 50 Hz AC. The two systems meet within the country – not just at a national border, as is familiar from many other European networks.

Feature	3 kV DC	25 kV AC, 50 Hz
Voltage	comparatively low	significantly higher
Current at equal power	high	lower
Overhead line	often built more heavily	can be built more slender
Contact strip on the pantograph	tends to be wider	tends to be narrower
Location in the Czech network	northern part of the country	southern part of the country

For operations, that has an immediate consequence: a vehicle that can only handle one system can’t cross the boundary. Either its operating area ends there, or the train gets a different traction vehicle. Dual-system vehicles are therefore everyday business in Czechia and not an exotic subject.

What happens at a phase break

Inside the train you’ll usually notice the event clearly: traction cuts out for a few seconds, auxiliary systems go quiet, and sometimes the lighting flickers briefly. Anyone who doesn’t know what’s happening could easily mistake it for a fault.

Reading the roof: single- or dual-system vehicle?

For spotters, the roof is the most interesting surface of an electric locomotive – and the most overlooked. The number of pantographs and the width of their contact strips relate directly to the electrification system a vehicle was built for.

The rough rule: systems with lower voltage need higher currents for the same power, and higher currents want more contact area. That’s why contact strips for DC systems tend to be wider. Vehicles that handle both systems often carry pantographs of different types side by side – a feature you can check well from photos.

Examples of vehicles that play a role in the Czech network can be found in the class database: the dual-system machine listed as Class 371, the multi-system locomotive of Class 380, and Class 162 in the RegioJet version. Class 380 and Class 162 both come from the works of Škoda Transportation. How to narrow down unfamiliar vehicles in general is shown in the guide to identifying classes.

Logging sightings with a system connection

For practical purposes that means: if you’re standing by a line and wondering why only certain types show up there, electrification is one of the first explanations you should check. On a section with only one electrification system, single-system machines run about completely unremarkably; a few kilometres further on, beyond the phase break, the same vehicles wouldn’t be usable at all.

That also explains why dual-system vehicles carry so much weight in Czechia. They make through-runs possible without a vehicle change having to be planned at a fixed point. For you as an observer that means one extra question with every sighting: is this machine tied to one section, or can it cover the whole country? The answer isn’t written on the vehicle – but the roof equipment gives a pretty good clue.

On the main line heading east you can check this directly: at Ostrava hlavní nádraží, long-distance trains from several operators arrive in quick succession. Heading south, the second major axis runs via Brno hlavní nádraží towards Vienna. And at Bratislava hlavná stanica, Czech, Slovak and Austrian vehicles arrive side by side.

Common mix-ups

• Electrification system equated with national border – in Czechia, the system boundary runs through the middle of the network.
• Every pantograph read the same way – type and contact-strip width differ depending on the system.
• Coasting without power mistaken for a fault – at the phase break, that’s exactly the normal case.
• Namesakes equated – entries like RegioJet AT carry a similar name, which on its own proves nothing.
• Livery used for identification – the data panel is what’s reliable. How to systematically work out the company from that is explained in the guide Who’s actually running it? Identifying railway operators.

Other operators run on the same axes too, for instance Leo Express and České dráhy – good reason to timestamp every sighting. For photo technique with fast-moving trains, the article How to take good photos of trains helps.

Conclusion

RegioJet a.s. is one of several companies in Czech long-distance travel – and the reason to engage with what makes the country technically distinctive. Two electrification systems, phase breaks in the middle of the network and an everyday full of dual-system vehicles: once you’ve understood that, you suddenly read Czech train formations and locomotive changes with completely different eyes.