Steven Berveling knows first-hand the damage a vehicle passing too close to a cyclist can do.
He was blown off his bike when a road train passed him as he rode in a 1200km cycling event near Katanning in October.
He broke his left femur, collarbone and ribs and had a brain haemorrhage.
Knocked unconscious when he hit the Great Southern roadside, he cannot remember much from that day and relies on the accounts of fellow riders.
But the aftermath is clear. Five months later, Mr Berveling's injuries are still healing.
The president of Sydney Cycling Club, Mr Berveling used to ride about 20,000km a year on the road and said the vast majority of motorists were terrific and courteous to cyclists.
"But there's a small minority who seem unaware of the danger they pose to cyclists," he said.
"With a lot of vehicles on the road, the one per cent who cause concern actually represent a significant number of vehicles.
"The danger happens when they are too close, and we need to acknowledge that all vehicles share the road and no one particular type of vehicle has priority or a greater right to use the road.
"I'm very conscious that I need to be super alert while I ride my bike because the cars are bigger than me and I take a defensive attitude to riding my bike."
Mr Berveling was in WA for a 1200km Perth-Albany-Perth ride with Audax Australia Cycling Club when injured while training for a 5000km, 24/7 race in the US.
Before his crash, the third of the WA ride, he was feeling "120 per cent".
He spent almost a month in hospitals in Perth and Sydney.
Holding the cracked helmet he kept as a reminder of what happened, he said the left side had a 5mm indent about the size of his palm.
But he strongly believes it prevented a more severe injury and said he was shocked that 25 bike riders treated in WA's State trauma unit last year were not wearing helmets.
Mr Berveling said his brain injury led to him not recognising some people he had known for years and a loss of motivation.
But of most concern for the self-employed barrister is a difficulty remembering certain words.
Mr Berveling believes proposed laws requiring one-metre separation from cyclists would help improve safety, as would additional infrastructure.
"But the primary concern is the need for increased awareness and sharing the roads," he said.