Power sources — electrical railroad tracks or power lines that are in close proximity can be causing WiFi interference. If you can try not to position your Wi-Fi router near power lines in the wall or close to the breaker box.

In 2026, trains themselves don't "attack" WiFi signals, but their construction and speed create a challenging environment for stable connectivity. Most trains are essentially large metal tubes (Faraday cages), which naturally shield and reflect radio frequency (RF) signals, making it difficult for external cellular data to penetrate the carriage. This is why many modern trains use "signal-boosting" glass or external antennas to pull in 5G signals. Furthermore, the speed of the train (especially high-speed rail like the TGV or ICE) requires the onboard router to constantly "hand off" its connection from one trackside cell tower to the next, which can cause momentary drops or "latency spikes." Within the train, the sheer density of passengers all trying to stream video simultaneously can overwhelm the onboard router's bandwidth. So, while the train doesn't "break" the WiFi, its physical structure and high-speed movement are the primary reasons your connection might feel sluggish or unstable compared to your home or office network.