Davison has been cleared to return for the twin-race Phillip Island 500 this weekend after a quick recovery matched by the remarkable repair of his destroyed Holden Commodore racer.

He was the main victim of a 12-car pile-up in the opening race of the previous Supercars event at Symmons Plains, near Launceston, on April 8, suffering a painful fracture in his spine.

His Tekno Autosports Commodore slammed into the side of Rick Kelly's Nissan Altima during the melee, registering a colossal 46 g on impact.

The force of the collision left Davison with mild concussion, severe bruising and a broken right-side transverse process, which is a small bony projection attached to each vertebra.

He was kept in hospital for 24 hours and not allowed to fly home to the Gold Coast until the Monday morning after the Saturday race.

Davison, 34, who won last year's Bathurst 1000 with Tekno team owner/co-driver Jonathan Webb, was fit enough to recuperate sufficiently by last Tuesday to pass the full medical examination required to resume racing at Phillip Island.

The final obstacle was a mandatory safety test at the track before the opening practice session on Friday, when he had to show officials he could perform an emergency exit from his car within the seven seconds limit.

Although still sore from the crash, he was able to extricate himself quickly and gain official approval to compete.

Davison's recovery from one of the biggest wrecks in Supercars history might have been in vain if the small family-run Tekno team hadn't been able to rebuild his car.

It was on its way back to the team's Gold Coast factory the day after the crash and after working through Easter, the crew repaired the extensive damage in time for the Phillip Island 500, which is being decided in 250-kilometre races on Saturday and Sunday.

Both Davison and his car were in good shape on their return at Phillip Island, with the Melbourne-born driver setting the fourth-quickest time in the opening practice session on Friday.

V8 veteran Craig Lowndes' Triple Eight Holden Commodore suffered heavy damage in a high-speed crash caused by the failure of its right front tyre.

Lowndes was uninjured, but his car required extensive repairs after it flew off the track into a safety barrier on the fast back section of the 4.45-kilometre oceanside Phillip Island circuit.

It was another setback for the popular driver, who was earlier docked 15 championship points following a review of an incident with Ford's Cam Waters in the second race at Symmons Plains.

Officials ruled that Lowndes was guilty of careless driving for bumping Waters out of the way on his way to fourth place.

Davison's Commodore was one of four cars crippled or written off in the 12-car crash that caused the opening leg of the Tasmania SuperSprint to be controversially completed with just four of the scheduled 50 laps completed.

While recorded as an official race, it was subsequently decided that no championship points would be awarded.

While Davison's car was able to be salvaged - and had to be because the team has no spare car and couldn't get a replacement in time - Kelly's Nissan was written off.

It had already been pummelled by hits from other cars as it pin-balled across the track as a result of the initial multi-car contact, with Davison's brakeless machine - which had lost its right rear wheel in an earlier contact - delivering the coup de grace.

Kelly is racing the Nissan's team's ageing spare car, which has been refettled and upgraded until a new machine can be completed in time for the Townsville 400 in early July.

Holden hero James Courtney is also racing a revived spare car after his HSV Racing Commodore was totalled amid the chaos at Symmons Plains.

Kelly suffered minor leg injuries in the T-bone collision with Davison, hastening Supercars officials' plan to improve driver leg protection.

Seat extensions that provide extra shielding for drivers legs to reduce side impact injuries will be mandatory for all cars from the Sandown 500 in September.

DJR Team Penske and Prodrive Racing have already adopted NASCAR-style extended safety pans that surround the drivers' legs in their Ford Falcons.

Using the experience of Team Penske in American stock car racing, DJRTP developed a local version after PRA's Chaz Mostert broke his left leg in an impact with the gear lever in his big crash in qualifying for the Bathurst 1000 in 2015.

VIRGIN AUSTRALIA

SUPERCARS CHAMPIONSHIP

WD-40 Phillip Island 500

Format: Super500 (2 x 250km races)

CHAMPIONSHIP TOP 5

Shane van Gisbergen (Commodore) 384

Fabian Coulthard (Falcon) 364

Jamie Whincup (Commodore) 333

Scott McLaughlin (Falcon) 330

Cam Waters (Falcon) 312

THE PROGRAM

Saturday

12.45pm-1.05pm: qualifying

3.45-5.25pm: Race 5 (57 laps/250km)

Sunday

10.50-11.10am: qualifying

1.50-3.30pm: Race 6 (57 laps/250km)

TV

Saturday

Live: Fox Sports 506/506 HD

9.45am-5.45pm

Highlights: One 8-9pm

Ten/Ten HD 11.30pm-12.30am

Sunday

Live: Fox Sports 506/506 HD

9am-4.30pm

Highlights: Ten/Ten HD 4-5pm

One 8-9pm