ONE of the two police officers being hailed as heroes for averting a tragedy on the South Eastern Freeway yesterday is being prosecuted over the alleged assault of one of SA’s richest men.

Constable Norman Hoy yesterday safely guided an out-of-control semi trailer through heavy traffic on the freeway and Glen Osmond Rd after he and his patrol partner noticed smoke pouring from its brakes near the Heysen Tunnel.

Risking their own lives the pair rapidly cleared traffic and guided the semi trailer to a standstill after a hair- raising 6km ride down the freeway.

Colleagues of Constable Hoy said he was “a dedicated police officer” who has been under considerable stress since being charged in late 2011.

“He is a terrific traffic officer, as we have seen,” one said.

“Notwithstanding the pressure he has been under he strives to ensure the public is safe when he does his job.”

Constable Hoy faces one count of aggravated assault following an alleged incident involving millionaire businessman Yasser Shahin in September 2010.

It occurred in the city when Hoy pulled Shahin over in his Rolls Royce and defected it because the window tinting was too dark.

Constable Hoy was later charged after Shahin engaged prominent silk Michael Abbott QC and lodged a complaint about the incident with the Police Complaints Authority.

The prosecution will allege there was physical contact between Constable Hoy and Shahin when the officer allegedly tried to prevent Shahin from re-entering his Rolls Royce.

The case has alarmed rank and file police who fear the outcome will impact their daily conduct. Many have questioned why Hoy was even charged with aggravated assault in the first instance.

The case is set down for trial in mid-2015. The charge is classed as aggravated because Hoy is a police officer.

Constable Hoy and his colleague were hailed heroes after escorting the truck to safety yesterday and preventing yet another tragedy at the bottom of the South Eastern Freeway.

The incident also coincided with a police blitz on heavy vehicles that found almost half of the trucks inspected had a range of defects.

The officers safely guided the truck, carrying a 40-tonne load, down the freeway and on to Glen Osmond Rd after noticing it with smoke pouring from its wheels about 11.45am on Tuesday.

Their potentially lifesaving actions came only three weeks after an out-of-control truck crashed into three cars at the bottom of the freeway, killing two people and injuring two others.

The officers were on a routine patrol on the freeway uptrack when they spotted the Victorian-registered truck, with smoke coming from it, as it exited the Heysen Tunnels.

In a series of events dubbed “extraordinary” by their superiors, the officers made a U-turn, activated their lights and sirens, and alerted traffic management to arrange control of the traffic lights at the bottom of the freeway.

Lights at the intersection were turned green to allow the truck, carrying a giant Caterpillar elevating scraper, to safely travel through the intersection at 70km/h while under police escort.

The truck was eventually able to stop safely on Glen Osmond Rd near the intersection of Wattle St. No one was injured.

Three weeks ago, Hallett Cove man Thomas Spiess and Ingle Farm woman Jacqui Byrne were killed when a fully laden sewage truck careered through the intersection at the bottom of the freeway at 152km/h.

Police described the incident as “a disaster narrowly avoided”.

It will be alleged the truck had oil in its air tanks, which caused the brakes to malfunction, and that neither trailer had working brakes. It will be further alleged the second trailer had cracks in the suspension and axle components.

A Victorian truck driver from Croydon South, 32, was reported for driving without due care and regulatory offences, while the company remains under investigation.

Police have confirmed the truck driver had told them he did not use the second and last arrester bed because he thought he could bring the truck under control.

Traffic Support Branch officer-in-charge Superintendent Bob Fauser said “that turned out not to be the case”.

Supt Fauser said the police investigation was now focused on the Victorian trucking company.

“The officers were on the freeway as part of our enforcement of the new regulations, but it is vital that the trucking industry plays its part in keeping all road users safe,” he said.

“This vehicle had malfunctioning brakes on the prime mover and no functioning brakes on the rear trailers — a completely unacceptable situation on our roads.

“We will continue to pursue all legal options with regard to this company and make no apologies for the focus we will continue to place on enforcing standards in the trucking industry.”

Supt Fauser said the two officers had prevented a potential disaster.

“The heavy vehicle travelled through the intersection at about 70km/h,” he said.

“The indications are that there was a brake failure under the weight. Clearly the fact that smoke was coming from the axles indicates that the brakes were under stress.”

The incident coincided with a police blitz — Operation Wayward — on heavy vehicles in Adelaide’s northwest that uncovered an alarming level of defects.

Heavy Vehicle Enforcement Section police and Transport Department officers inspected and monitored heavy vehicles in the industrial areas of Wingfield and Cavan.

A vehicle inspection site was set up on Churchill Rd at Dry Creek, where 31 out of 70 vehicles were defected because of brake, steering or suspension issues.

Supt Fauser said the 31 defects were “major” and the vehicles would need to be repaired and reinspected before being allowed back on the road. He said those results showed some in the heavy vehicle industry were not heeding the warnings.

“We know that most drivers and businesses take safety very seriously. However a few don’t. It is those drivers and operators police are targeting,” he said. “Recently we saw the tragic death of two innocent motorists after a truck crashed.

“Truck drivers and their companies have a responsibility to do the right thing as the size and weight of one of the vehicles in a crash increases, so does the severity of the crash.”

Transport Department compliance and investigations manager Stephen Smith said department personnel would support police with the blitz.

Road Safety Minister Tony Piccolo said it was too early to know why it occurred but urged the need for vigilance.

“Foremost, I want to express my sincere thanks to the ... officers and the DPTI Traffic Management Centre for their excellent work,” he said.

South Australian Road Transport Association executive director Steve Shearer called for a full investigation into all out-of-control truck incidents in the past three to five years.

Mr Shearer said the investigation should highlight what caused the incidents and the decisions made by drivers, including why they did or did not use arrester beds.

“In all probability it was only through the quick actions of the police and the traffic control centre that more fatalities at the Glen Osmond Rd/Portrush Rd/Cross Rd intersection were avoided,” he said.

Mr Shearer said the trucking industry wanted an automated system to detect faulty trucks appearing to be in danger, which would immediately trigger an emergency change to lights at the bottom of the freeway and clear traffic.

Opposition road safety spokesman Corey Wingard commended the “outstanding work” of police.