They were still trying to figure out when and where they could drive on the 30 miles of lanes, designed to whisk 82,000 athletes, officials, VIPs, sponsors and media to venues on time.
One driver said he spent much of his journey from east London stuck in a bottle-neck while casting an eye at an empty lane which was not being used by any of the Olympic community.
"They've closed off the Games Lane, but nobody was using it," said Ross Keeling, a call-out engineer, whose normal 40-minute journey had become two hours.
"It was a pain the neck," he added. "We just have to sit and watch the empty lane."
Dubbed "Zil" lanes after Soviet roads reserved for black limousines carrying senior Communist party members, the specially designated lanes were introduced after athletes became stranded in traffic jams at the 1996 Atlanta Olympics.
They are resented by many Londoners who already have to endure narrow, log-jammed streets.
Alex Grebnev, 32, who works in a bank in central London, said he faced the tricky choice of driving in a Games Lane or a bus lane - both of which can carry a hefty fine.
"It was a bit confusing not knowing which one to drive in," he said. "Luckily it was 2am at the time."
The Games Lanes are part of a larger 109-mile Olympic Route Network which prohibits stopping or loading and some right-hand turns.
Some delivery van drivers have planned ahead, and worked out which side roads they can use for parking.
Some firms have also stocked up on supplies to avoid potential trouble, while traffic woes had been eased with schools being on holiday.
Van driver Perry Fletcher showed the inside of his van which was virtually empty despite it being mid-morning.
A few black cabs have swapped the taxi drivers' Bible, the ubiquitous London A-Z, for the new Olympic route guide to help.
"You've got to keep your eyes open for the road markings," taxi driver Allan Williams, 68, said.
"The problem is they are all white. It's early days. I've said I would give myself two days from this Friday to see how it goes. If I get stuck I'll give up. It will be a waste of time, nobody wants to sit in a cab that isn't moving."
Peter Hendy, commissioner at London's public transport authority Transport for London, denied motorists would be confused in an interview with Reuters earlier this month.
"It is quite clear to me already that from the markings we have put down without all the signage that people can very clearly see what's there and I don't think people will be confused," he said.
Olympic organisers LOCOG said traffic was moving and athletes had been getting to venues for training.
"Up until this morning it's been good," a spokeswoman told reporters at the daily briefing.
"The traffic is moving, the lanes are working well."