Speeding is the most common rule broken on Western Australian roads, according to the state's drivers.
More than a third of respondents (37 per cent) to an RAC survey of its members said they regularly saw other motorists break the legal speed limit.
RAC general manager corporate affairs Will Golsby said the results, in which people could nominate more than one answer, were alarming and Western Australians should put their safety first and obey the rules.
WA had the worst road fatality rate of any state in Australia, he said.
Last year, 195 people were killed on West Australian roads and speed was the leading cause of crashes.
"A further quarter of respondents said they see people tailgating and using their mobile phone behind the wheel - two dangerous habits which have been shown as being the main contributors to rear-end crashes," Mr Golsby said.
The Top 10 Most Commonly Broken Road Rules:
* Speeding (37 per cent)
* Failure to indicate (33 per cent)
* Tailgating (27 per cent)
* Using a mobile phone (25 per cent)
* Running red or amber lights (21 per cent)
* Incorrect use of roundabouts (20 per cent)
* Incorrectly merging (19 per cent)
* Failure to keep left (10 per cent)
* Changing lanes over a solid continuous lane marking (9 per cent)
* Failure to give way (9 per cent)
© AAP 2017