"London's entire transport system is likely to come under strain during the two weeks of sport, with about 5.3 million people visiting the Games, the committee said in a report.
The busiest days are likely to see more than one million Olympic-related journeys on public transport.
It would not be easy to absorb the extra demand because the network already operates near to capacity, the committee said."
Employers are being urged to ask employees to stay home or work remotely during the two week period of the Olympic games to cut down on the strain.
