LONDON (AP) — Roads snarled in London, Paris and several other major European cities Wednesday as taxi drivers and train workers protested new technology they say endangers passengers and gives upstart enterprises an unfair advantage.

Drivers of London’s famed black cabs refused to pick up fares and drove at a snail’s pace through Trafalgar Square — creating nightmarish gridlock — and travelers in France were hobbled not only by the taxi slowdown but also by strikes on the national train network and Paris commuter lines. Madrid, Barcelona and Berlin were hit as well.