Transport chiefs insist they were not embarrassed by the failure of two train lines that caused major delays following a dress rehearsal of the London 2012 opening ceremony.
The closure of London Underground's Central Line and an Overground line affected the 60,000 people who had come to the Olympic Stadium.
Transport Secretary Justine Greening rejected a suggestion that she should be embarrassed about the problems.
Greening told a news conference: "I don't think that's right. We got everybody home. It was a successful dress rehearsal but it shows on a transport system as complex as London's things do go wrong. What we showed last night actually was even when things do go wrong we still delivered a transport system for people to be able to get home.
"Although one line was down the rest of them were working and that's part of the resilience we have got."
Transport for London commissioner Peter Hendy apologised for any delays and stressed the line failures showed there was flexibility in the system.
Hendy said: "Obviously I'm sorry that two lines serving the Park went down. The rest of them didn't and we got the Overground back up and running.
"What it demonstrates is there's a huge amount of redundancy in the system. There are 10 rail lines serving this park and we will get people there and back on all of them."
The Olympic route network is switched on at 6am on Wednesday with special Olympic lanes reserved for vehicles carrying athletes and officials. Hendy advised motorists to avoid driving in central London and for Games visitors to plan their journeys beforehand.
He added: "We are expecting at least one million extra people in London every day and an additional three million journeys on public transport. Our advice to Londoners and people coming to the Games is to plan in advance and you will have a successful time."