This is the 7466th most frequent Catalan word.
aturen
"Aturen" means "they stop" or "they halt" in English.
'Aturen' in this sentence is used to mean 'stop' in the context of vehicles responding to a traffic control signal.
Els vehicles s'aturen quan el semàfor es posa vermell.
Vehicles stop when the traffic light turns red.
Here 'aturen' indicates that a process is halted or paused because of external factors.
Les obres s'aturen mentre esperen els nous materials.
The construction works are paused while waiting for new materials.
In this case, 'aturen' suggests taking a moment to pause an action in order to pay attention to something else.