The massive multi-car crash was blamed on a dense fog blanketing the Sheppey Crossing bridge connecting the Isle of Sheppey with the mainland part of Kent.
Though officials said it was "truly miraculous" that no one was killed, eight people were seriously injured and at least 60 people received minor injuries.
"There are no fatalities but ambulance crews are dealing with a large number of walking wounded casualties," Kent Fire and Rescue Service said in a statement. "Firefighters have used hydraulic cutting equipment to release five people from their vehicles."
Witnesses said it was hard to see through the fog, but that some people were driving either too fast or without their lights on.
Some were "driving like idiots," one witness told Kent Online.
Another credited a truck driver with purposefully blocking the road with his truck -- a move that could have saved lives.
"He was going the other way and ... he's gone down to the end of the carriageway, gone across the roundabout and actually blocked off the road so no more cars could actually enter the dual carriageway before the emergency services got there," driver Chris Buckingham told Sky News.
"Whoever that guy is I'd like to shake his hand because he's probably saved lives," he added.
While authorities said it was too early to identify the exact cause behind the crash, they conceded that the weather probably played a role.
"It was... very hazardous," Chief Inspector Andy Reeves told BBC News. "It was described to me as a very thick fog and it was certainly low visibility at the time."
Carnage on the a249: not nice 60-70 cars involved. pic.twitter.com/sR2rETIpHm— Chris Buckingham (@westhambucky) September 5, 2013