The first high-speed Javelin train service serving the Olympic Park was running late today - after the driver called in sick.
The Southeastern train company had designated the 7.04am from St Pancras station in London to the park in Stratford as the beginning of the service.
But the 140mph Japanese-built train did not leave Stratford until 7.09am.
A spokeswoman for Southeastern said the 7.04am had left late because the company had to get a replacement driver, as the booked driver was unwell.
She went on: "We have drivers on standby for this reason; 99% of our trains arrived on time this morning."
Elsewhere, the AA said that traffic in central London was especially heavy as vehicles were forced to stay out of designated Olympics lanes for Games traffic.
Taxi drivers have previously demonstrated outside the Houses of Parliament London taxi drivers have been banned from staging another protest as part of their campaign against being prevented from using the Olympic lanes.
The demonstration had been planned for Hyde Park Corner at 5pm, just hours before the opening ceremony of the Games.
But the Metropolitan Police have now imposed restrictions on holding protests on any part of the Olympic Route Network from 4pm until 3am.
One of those on the delayed Javelin train was a chef working in a hospitality area at the Park. He has been travelling to Stratford from Luton via St Pancras for the last few days.
He said: "Not one of my trains has been on time. It was 15 minutes late one day."
Once under way, the delayed 7.04am service raced to Stratford International Station in east London in under seven minutes.
Eight Javelin trains an hour will run between St Pancras and Stratford and Ebbsfleet International station in North Kent during the Olympics.
Between 11pm and 1.59am there will be 12 trains an hour, with a half-hourly shuttle between Stratford and St Pancras between 2am and 5am.
The service will run until Sunday August 12 and will operate for the Paralympics from Wednesday August 29 to Sunday September 9.
Southeastern expects to transport 25,000 people an hour to and from Stratford. Those with Games' travelcards can use them on the Javelin service.
