Transport for London took to Twitter to say roads and transit will be "exceptionally busy" on the third day of the Summer Games.
According to The Associated Press, there were few signs of trouble early Monday, with rail lines operating properly and some highways experiencing lighter traffic than expected.
"Journey into work, thankfully seamless and rather pleasant," said commuter Aysem Monaco on Twitter.
Leon Daniels of Transport for London said everything was going well, and downplayed the scenes of long lines of cars crawling into the city.
He said there are always queues on some of the main roads coming into London on a Monday morning.
"But they're just about where we'd expect them to be, anyway. We're content with that."
But Steve McNamara, of the cab drivers association, said those traffic jams prove that planners have failed.
"They're constantly appearing on news reports telling you all is well, whilst pointing at screens of gridlocked traffic," he said. "What they say and what you see are two totally different things."
Transit authority gives heads-up on 'hot spots'
London's subway, the Tube, saw some delays and suspensions last week, while road traffic was also disrupted by Olympic lanes reserved for athletes and officials.
The transit authority is trying to ease any inconvenience by providing tips on planning routes, updates on travel disruptions and a list of transit "hot spots" expected to be busier than usual.
The London Organizing Committee of the Olympic and Paralympic Games (LOCOG), which has been taking heat over empty seats at some venues in the early days of competition, says there are 34 Olympic venues. Sporting events are taking place in venues across London, from the Olympic Park in the east, to Wimbledon and Wembley Stadium in the west.
The Games opened Friday night with the opening ceremony.
Canada earned one medal the first two days of competition, a bronze in women's three-metre synchronized diving, on Sunday.Suggest a correction