BUSIER than usual pre-poll voting in Ballina caused traffic mayhem yesterday with a four-car crash outside the voting booth on River St.

Ballina Greens candidate Tamara Smith said she narrowly escaped being knocked over when a white sedan pulled out into River St and set a chain of events in motion which involved a yellow Audi, another red sedan and a taxi bus.

"Anyone could have been killed," Ms Smith said.

"I was literally three metres from the accident."

An Ambulance NSW media spokeswoman said paramedics were called to the scene just after noon to reports of a four-car collision and treated one man aged in his 70s for shock. He did not require transport to hospital.

Nationals candidate for Ballina Kris Beavis also watched the crash unfold.

He said the collision occurred during a period of unusually high traffic activity at the office - more like what was expected at a polling booth on Election Day - with lots of voters pulling in and out of the busy road.

"Fortunately no-one was hurt, but we've sort of sat here for a couple of weeks wondering if that was going to happen," Mr Beavis said.

Ms Smith said the site was an accident waiting to happen for weeks and candidates had made complaints to the New South Wales Electoral Commission to no avail.

"There's nowhere to park except to back in on River St, which is like a highway," she said.

"It's an OHS and public safety nightmare," she said.

"It's outrageous … it was waiting to happen."