Twenty-nine people in total were taken to nearby hospitals by ambulance for treatment after a single decker First Bus overturned on the A739 slip road from the Clyde Tunnel heading to the west-end of Glasgow.
The access sliproads and the Expressway have since reopened, Glasgow City Council have confirmed.
The high loop and slip road from Victoria Park Drive South onto the Clydeside Expressway was closed eastbound to all traffic following the incident which happened at around 7pm on Sunday.
Pictures on social media showed passengers being treated at the roadside with emergency services in attendance.
Five people, including the driver of the bus, were taken to the Queen Elizabeth University Hospital in Glasgow where staff described one person as critical and two others as in a serious condition.
The other injured people were taken Glasgow Royal Infirmary and the Royal Alexandra Hospital in Paisley.
A Police Scotland spokesperson said: ”Twenty-nine people were taken to hospital by ambulance for treatment. Twelve were subsequently released following treatment. Seventeen people are still being treated in hospital for a variety of injuries, three of whom are classed as serious but stable.”
Inspector Darren Faulds from the Divisional Road Policing Unit based at Helen Street, whoc is leading the investigation into the cause of the crash. He said: “After officers arrived at the scene, they spoke to 28 passengers and the driver of the bus.
“Our investigation is continuing today into the cause of the crash. The bus involved will be fully examined and officers are gathering and studying CCTV footage from the area to assist with their enquiry.
“At this time, I would urge anyone who may have been on the bus and left prior to arrival of the emergency services, or anyone who witnessed the crash take place to contact the Divisional Road Policing Unit at Helen Street through 101 quoting reference number 3617of 29th April.”