Last weekend's Channel Tunnel travel chaos showed that the set-up of Eurostar and Eurotunnel "does not meet the information needs of passengers", the tunnel's Anglo-French supervisory body said today.
Both companies must jointly develop "satisfactory solutions in this matter", added the Channel Tunnel Intergovernmental Commission (IGC).
The commission said "passenger comfort should be understood in the broadest sense".
This included "material transport conditions, evacuation conditions and information", with the commission saying that "providing this comfort is an obligation for railway undertakings and for Eurotunnel".
Hundreds of passengers were trapped in the tunnel for hours when five high-speed trains became immobilised after extremely cold conditions in northern France led to snow affecting their electronics.
Passengers later spoke of nightmare conditions of cold and hunger.
Channel Tunnel Folkestone to Calais shuttle train company Eurotunnel suffered from the knock-on effect of the chaos.
The ICG said today that it had held an extraordinary meeting yesterday to analyse last weekend's events.
This was attended by former Eurotunnel commercial director Christopher Garnett and by French rail official Claude Gressier, who are conducting an independent inquiry into the debacle.
The commission said it had heard initial reports from Eurostar and Eurotunnel.
The commission said today: "The IGC wished to express its great sympathy to Eurostar passengers and also to those on Eurotunnel shuttles who were victims of these events."
The commission added that, after the meeting, it had "stated that the present organisation of the operators does not meet the information needs of passengers, and demanded of the two organisations that they jointly develop satisfactory solutions in this matter".
The ICG said it "noted" Eurostar's explanation of snow getting into the motors of the trains and also noted the measures the company had put in place to avoid a recurrence.
No Eurostar trains were able to run on Saturday, Sunday and Monday while modifications were made and tested.
Since then, the company has been able to run around two-thirds of its daily services between London and Paris and Brussels.
The independent report into the chaos is expected before the end of January and will be sent to UK and French ministers.
A Eurotunnel spokesman said: "We note the comments of the IGC.
"Eurotunnel mobilised all its resources on Friday night to ensure the safe rescue of the passengers of the five Eurostar trains."