Three-time Indianapolis 500 winner Dario Franchitti has been forced to quit motor racing on medical advice after having suffered multiple injuries in a horrifying crash.

The 40-year-old Scottish driver broke two vertebrae in his spine, suffered a concussion, two broken ribs and a broken right ankle at the Grand Prix of Houston in October and has now been told by his doctors to give up the sport.

“One month removed from the crash and based upon the expert advice of the doctors who have treated and assessed my head and spinal injuries post accident, it is their best medical opinion that I must stop racing,” Franchitti said in a statement.

“They have made it very clear that the risks involved in further racing are too great and could be detrimental to my long term well-being. Based on this medical advice, I have no choice but to stop.”

Franchitti won 31 Indy car races and the famed Indy 500 in 2007, 2010 and 2012.

“I was looking forward to the 2014 season with Target Chip Ganassi Racing, with a goal of winning a fourth Indianapolis 500 and a fifth IndyCar Series championship,” he added.

“Hopefully in time, I’ll be able to continue in some off-track capacity with the IndyCar Series.”