The appointment of an independent panel to consider how to improve road safety in the wake of last week's fatal bus crash on the Tuen Mun highway will help ensure lessons that may save lives are learned from the tragedy. The three-man Independent Expert Group will focus on the many pressing safety concerns raised by the accident, in which 21 people died when a double-decker bus plunged into a ravine. The panel's terms of reference are broad, including highway design and traffic management. The scope of the inquiry is expected to extend beyond the stretch where the accident happened, and the conclusions reached could have wide-ranging implications for road safety standards and public transport arrangements across Hong Kong. Among measures the panel might consider are whether the roadside barriers, which were unable to prevent the bus toppling over the edge, should be strengthened or redesigned; how efforts to deter dangerous driving and speeding can be made more effective; and whether there is a need to divert heavy vehicles from potential danger areas. What the panel will not do is to seek to place blame or to establish the cause of the bus crash. While this would seem to limit the scope of the inquiry it at least ensures the experts will not trespass on the criminal investigation that the police are already conducting. Chief Executive Tung Chee-hwa has acted decisively by quickly setting up the panel and making it independent. There will be no government minister presiding over it. He clearly sees the wisdom of taking such a step. It should mean the experts can carry out their work objectively and free from any allegations of conflict of interest. It gives the panel credibility and will make it easier for the experts to fulfil the task of putting forward recommendations that will prevent a similar tragedy in the future. Unfortunately, Mr Tung's enthusiasm for independent probes has not extended to other areas of great public concern, notably the government's handling of the Sars outbreak. The bus crash involved a tragic loss of life - like Sars. It warranted a review of government policy - like Sars. It called for objective consideration of measures to prevent such a disaster ever happening again - like Sars. Yet the panel looking into the outbreak, rather than being independent, is to be headed by the man most closely associated with the government's handling of the crisis, health chief Yeoh Eng-kiong. There is one factor that may explain the different approaches. The one examining the bus crash is less likely to come up with information or findings that will damage the government than is the one looking into its faltering handling of Sars. What is good for one, however, is good for the other. Mr Tung should establish an independent inquiry on Sars.