UK drivers

In the UK, it is recommended that drivers should turn off their car 1 when they expect to be stationary for more than 1 minute. To encourage drivers to turn off their engines while waiting at rail crossings, the Kent city council placed a permanent sign at the crossing asking drivers to "please switch off your engine when barriers are down to help improve air quality." 2, drivers had to wait between 2 and 3 minutes to cross after the barrier had gone down. However, the sign didn't seem to be convincing 3 drivers to switch off their engines. "Although some research suggests that signs alone can change behaviour, the message on this sign was designed simply to be an informational request and was not guided by any particular behavioural theory," the researchers explain. So the 4 team, led by Rose Mellady of the University of East Anglia, designed an intervention study.