Former F1 driver and two-time CART champion, Alex Zanardi has been severely injured in a road accident whilst taking part in a handcycling event.

Following today's accident in Pienza, in which he is understood to have sustained a "severe head injury", the Italian was airlifted to Siena's Santa Maria alle Scotte hospital.

The Italian, who raced with Jordan, Minardi and Lotus in F1 before heading off to the US where he twice won the Champ Car title, returned to F1 with Williams in 1999 but with little success.

Returning to Champ Car he was involved in a horrific accident in the German round at the Lausitzring, the Italian losing both his legs.

The accident and its consequences however resulted in a form of re-birth for Zanardi, who returned to racing, enjoying success in the World Touring Car Championship and Blancpain Sprint Series. He even returned to the Lausitzring to symbolically finish the infamous race that almost cost him his life.

Zanardi then targeted handcycling, winning gold in the Men's Individual H4 Time Trial and H4 Individual Road Race at the 2012 London Olympic games and claiming his third Olympic gold in Rio when he beat Australia's Stuart Tripp in 2016, despite being 10s down at the halfway point of the 20km H5 Time Trial.

It's understood Zanardi was hit by a truck after accidentally veering into the opposite lane in a downhill section of the road course and subsequently rolling his handcycle.

"We were in curves, on a not too difficult descent," Italian Paracycling National Team coach, Mario Valentini told Corriere della Sera. "Alex lost control of the handbike, rolled over twice and impacted a trailer truck.

"The collision was terrible," he added. "The paramedics recovered it, it was very serious. The helicopter was unable to land so the ambulance took him to a nearby pitch where the pilot of the aircraft managed to get off and transport it to Siena. It was terrible."

"You have never given up and with your extraordinary fortitude you have overcome a thousand difficulties," wrote Italian prime minister, Giuseppe Conte on Twitter. "Come on Alex Zanardi, don't give up. All of Italy is fighting with you."

"I am so anxious and frightened about Alex Zanardi that I'm holding my breath," tweeted fellow racing legend, Mario Andretti in response to the news. "I am his fan. I am his friend. Please do what I'm doing and pray pray for for this wonderful man."

Thoughts echoed by Pitpass and its readers.