A failure by transport bosses to upgrade one of Croydon's most dangerous crossings was partly to blame for a tram collision that left a pedestrian with life-changing injuries, investigators have ruled.

A 28-year-old woman was airlifted to hospital after being struck by a tram and dragged along the tracks at Sandilands tram stop in Addiscombe on May 16 last year.

She spent weeks in hospital after suffering multiple serious injuries in the collision, which saw her become trapped beneath the tram.

Fifteen firefighters worked for nearly an hour to free her.

A report into the accident, published on Friday by the Rail Accident Investigation Branch (RAIB), said TfL had failed to conduct safety upgrades at the Sandilands foot crossing despite a review 12 months earlier highlighting it as the most dangerous in central Croydon.

It also said that TfL had used flawed methodology for assessing risk at tram stops, leading to potential danger at Sandilands being underestimated, and that trackside equipment cabinets may have obscured the woman's view of the oncoming tram.

The woman, who had been rushing to cross the tracks to catch a tram heading in the opposite direction, had not looked to see if any trams were approaching.

She only survived the collision because she fell into a gap between the train and the track.

RAIB urged TfL to review all its foot crossings to look for potential obstructions to pedestrians' views. It also recommended that TfL improve its risk assessment system.

Barriers and warning signs have already been installed at the Sandilands stop since the accident.

Martin Brown, head of safety, health and environment for TfL, said: "This was a terrible accident and our thoughts are with the victim, her family and her recovery.

"We and the tram operator, Tram Operations Ltd, adhere to all the Office of Rail Regulation (ORR) safety rules on tram operation and we will always accept any suggestions to improve safety on the Tramlink network.

"We are seeking further clarification from the Rail Accident Investigation Branch and the ORR about what safety measures they both wish to see put in place for the future and will work with them to implement those measures as quickly as possible."