Updated: A frustrated bus driver has unleashed an angry tirade after an ambulance blocked the road at the scene of a car crash in Perth’s southern suburbs.

Passenger Natasha Busono filmed the furious exchange between the driver and what is now believed to be a tow truck driver while on the 507 bus to Carousel Shopping Centre just before noon on Saturday.

Ambulance crews were responding to a priority one incident where a car had collided with a tree and then crashed through a brick wall.

Ms Busono said the bus was blocked from proceeding on its route by an ambulance parked on the roadway but the driver’s reaction was over the top.

“There was no prior communication as to what had actually happened, as to whether anyone was injured or not, and so after a couple of minutes ... the driver got very frustrated and started honking or yelling at one of the paramedics,” she said.

“Then he told one of them to drive off so at least he could do his job, which I get, but considering the situation and that he didn’t even know what the situation was I think it was quite unwise.

Ms Busano said the driver was rude and his behaviour uncalled for.

“He simply could have told them ‘hey guys, could you tell me what the situation is about and would it be possible if you could move your vehicle so I could drive through and hope everything is OK’,” she said.

“That wouldn’t have been a major issue at all but that clearly wasn’t the case.

“After the vehicle drove away, it was parked to the other side, it wasn’t enough for the driver, he just started to open the doors to talk to one of (those on the scene) and just wasn’t very nice.”

Ms Busano said the incident was out of the ordinary because bus drivers in her experience were usually “super friendly and super lovely”.

St John Ambulance duty manager Stephen Luke said after reviewing the vision he believed the ambulance was parked appropriately.

He said under the road traffic code emergency vehicles, including ambulances, can park anywhere when responding to an emergency.

“The ambulance is normally parked at a scene to assist in the protection of the scene and people working around the incident,” he said.

“All road users and the public should understand it takes time to treat people and remain patient when they see an emergency ambulance blocking any area and allow the crew time to assess the patient’s condition and the extent of the patient’s injuries and provide appropriate medical treatment.

“The ambulance will stay close to the scene so the crew is protected (and all persons working in the incident area) and to ensure the ambulance is close enough and safe enough to load the patient once they have stabilised the patient before heading to hospital.”

Transperth spokesman David Hynes said the incident was disappointing.

“I think it is disappointing, but hardly newsworthy, that two people doing good work in providing important services to the community cannot resolve a relatively minor dispute without trading insults,” he said.

“On the face of it, this is not the sort of behaviour we expect of our bus drivers. I am not prepared to comment further until I have had a chance to review a report on the matter from the relevant bus contractor.”