Franchitti and two other fans were sent to the hospital, but the 40-year-old Scot sustained injuries so severe that doctors have advised him to quit racing.
"One month removed from the crash and based on 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 Thursday.
"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. Racing has been my life for over 30 years and it's really tough to think that the driving side is now over," he added.
Franchitti's estranged wife, Ashley Judd, rushed to his side after the crash, tweeting: "Thank you for the prayers for @dariofranchitti I have only clothes on my back & the dogs but that's all that we need & we are on our way."
Her response has since led to speculation that the pair will reunite.
You can read his full statement in the Twitter message below:
A sad day but I'm eternally grateful... pic.twitter.com/h9ozPEOf7S— Dario Franchitti (@dariofranchitti) November 14, 2013