Train drivers' union Aslef has called on tram operation to be taken under the direct control of Transport for London (TfL).
The Rail Accident Investigation Branch (RAIB) today released an interim report into the Croydon tram crash last week where seven people lost their lives and 51 were injured after a tram derailed.
The report found that the tram was going 43.5mph in an area where the speed limit was 12mph.
Finn Brennan, Aslef's district organiser, said:
While individuals will be held accountable for their actions, it is clear that the lack of adequate safety systems were at the root of this dreadful accident.
On the mainline railway, or London Underground, long established, tried and tested technology such as Train Protection Warning System (TPWS) or Automatic Train Protection (ATP) is in place to ensure that a train travelling too quickly in a potentially dangerous area will be slowed and stopped.
This technology is not in place on Tramlink. If it had been then this awful event could have been avoided.
He added that the operation of Tramlink "should now be taken under direct control of TfL so that immediate steps can be taken to implement the recommendations of the RAIB".
Transport for London's (TfL) London transport commissioner Mike Brown said: "I thank the RAIB for their thorough and swift interim investigation. Our engineers have now repaired all track and other equipment and have run trams over the repaired section.
“We will follow the RAIB’s advice and, before service is resumed, will implement additional temporary speed restrictions and associated signage near Sandilands to supplement existing safety arrangements."
TfL is continuing to carry out a thorough safety assessment and will only resume services "once that rigorous assurance process has been completed".
FirstGroup currently operates the trams for TfL. Commenting on the RAIB report, chief executive Tim O'Toole said: "On behalf of everyone at FirstGroup I would like to express our condolences to the bereaved families and friends and to those who were injured."
He said that the company was working with TfL to "follow the RAIB’s advice and provide clear instruction on this to our drivers".
In response to Aslef's call for control of the trams to be shifted, a First Group spokesperson said: "Our priority is to work with TfL and the authorities to provide assistance in any way possible to those who have been affected and to the investigations. As these investigations are ongoing it would not be appropriate to comment further on these matters.”
Chief inspector of rail accidents Simon French said the inquiry would look at the wider context of the incident, including the sequence of events, the way the tram was driven, the infrastructure and how people received their injuries.