This should inspire confidence next time you board the Shenzhen Metro: trains on the Shekou line toward Luohu District temporarily stopped November 1 after suspected signal interference by passengers’ use of mobile networks, according to Southern Metropolis Daily.

The problem started at 8:15am and continued until 9:30 am.  All subway trains travelling from Chiwan stopped for one to two minutes, inconveniencing thousands of passengers. According to the operator, the signal was interfered with by unidentified mobile networks, and all trains are programmed to slow down or halt in such circumstances.

That evening, anonymous insiders told media that the unidentified networks were being used by passengers on their mobile phones. An engineer said the network had the same frequency range as the one used by the metro company.

In September 2011, hundreds were injured in a subway accident in Shanghai. Two months earlier, a high speed rail crash in Wenzhou City in Zhejiang Province caused much public anger, and in recent days was brought up in an impassioned debate about the quality of infrastructure in China between Martin Jacques of the BBC and Charles Custer of Chinageeks.

Fortunately, this incident turns out to have been a minor one.