It is pretty well known that Perth drivers hold the award for being the worst drivers in Australia.
Despite there being significantly less cars in Perth than Sydney or Melbourne, Perth drivers manage to achieve almost twice the minor accident/bingle rate—involving at least $1,000 worth of damage but where nobody had to go to hospital—than either of those cities.
Serial lane changers—drivers who continue to change lanes despite it not being required for them to exit the traffic flow (they are just changing lanes because there is a gap and changing lanes appealed to them)—are far more prevalent in Perth. Serial lane changers are the primary causes of bingles in traffic flows, which contributes to the first point above.
Not only does Perth have the highest rate of serial lane changers, Perth drivers changing lanes are 20 percent less likely to indicate during the lane change than for Sydney or Melbourne drivers.
Additionally, lane-change-cheating is far more prevalent in Perth. This is where a driver knowingly drives in the wrong lane in order to get ahead of the traffic flow, and then has to push their way into a different lane—usually at the last possible opportunity—to get into the lane they really should have been in to begin with. Lane-change-cheats force otherwise flowing traffic to slow or stop in order for them to complete their cheat.
There was a time when lane-change cheats were almost exclusively taxi drivers, but over the last 10 to 15 years it has become more common for regular drivers in Perth to lane cheat than for taxi drivers.
Merging! Perth drivers are notoriously hopeless at merging. This is despite a number of recent campaigns by the WA government to try and correct this failing; even going to the lengths of slightly changing the merging rules at one stage to try and make it easier for drivers to remember how to merge.
The two main mistakes that merging drivers make are: (1) not getting up to the merge speed before trying to merge, and then (2) braking hard to slow down at the time of merge in order to merge ‘more safely’.
When merging, you must be travelling at the speed of the traffic you intend to merge into. This is basic common sense. You obviously cannot merge into a traffic stream travelling at 100 kph if you are doing 80 kph. That is never going to work out well. It forces other drivers in the main stream to brake when they should not have needed to. This in turn can cause the drivers down the traffic stream to have to brake unexpectedly; and this can result in a bingle (again, see first point relating to bingles).
I don’t know what the answer is, or why Perth drivers drive the way they do. But I witness all of the above every day going to and from work.