LONDON (AFP) Travellers in Britain are facing disruption for a second consecutive day Tuesday after heavy snowfalls, as questions emerge about how the authorities responded to the deluge. Snow has now stopped falling in most parts of southeast Britain, where around 10 centimetres (four inches) of snow fell overnight Sunday and Monday, the most for 18 years. Conditions there are now turning icy, while the snow has headed north, affecting areas like the Pennine mountains in northern England and the Scottish Borders. Passengers using London's two main airports, Heathrow and Gatwick, are facing "significant delays and cancellations" after serious problems Monday while airport operator BAA also reported delays at airports including Edinburgh and Glasgow in Scotland. Drivers are being told by the Highways Agency not to take their cars out unless the journey is essential. It says most roads are running well but more snow is expected during the day, particularly in the north, and conditions in some places are icy. Most national rail routes are operating but train companies in the southeast are operating revised timetables, rail infrastructure operator Network Rail said. Four out of 11 of London's Underground train routes are either suspended or part suspended following the snow. Most bus routes are operating except where road conditions are still dangerous. Commuters and business leaders are questioning why the snow has caused such disruption despite it being forecast for several days beforehand. David Frost, director-general of the British Chambers of Commerce, said up to a quarter of employees did not go to work Monday, adding that images of snowbound Britain were embarrassing. "All the European channels were showing images of London at a complete standstill, which was not a very positive image for the UK," he told BBC radio. "I wonder whether we have become a bit too complacent... when something like this does happen, we are caught very much on the hop."