Delivering hundreds of thousands of spectators, athletes, officials and workers to the Olympic Park and other venues around the capital on time is a major challenge for any city bidding to host the Games.
But the London 2012 bid team claims the capital is already better equipped than most, with its extensive Tube and commuter rail system able to move spectators around rapidly.
All the London venues are served by at least one railway or underground station, and many have more, so little in the way of Olympic specific transport infrastructure will be built.
This is in marked contrast to Sydney in 2000 or Athens this year. Each had a single, purpose built rail line linking the main stadium with the city centre and other venues. Each ran the risk of major spectator delays if the line broke down.
London's aim is to deliver 78% of spectators by rail, 16% by coach and the rest on foot, bus or bicycle. Driving to venues is out of the question as parking close to the Olympic Park will be banned for all motorists except those with a resident's parking permit or a disabled sticker.
Most improvements to the rail network were already programmed before the government decided to put in an Olympic bid. The public private partnership to upgrade the Underground is already taking care of the need to double capacity on the Jubilee Line.
This will be completed before 2012 when moving block signalling will finally be introduced, reducing train headways.
Network Rail's north London Line between east London and Richmond will also be upgraded to carry eight car trains, running more frequently. The only Olympicspecific change here is that freight operators might be asked to reduce daytime use of the line, so more passenger capacity can be squeezed out.
By Olympic year, 2012, the Channel Tunnel Rail Link will have been open for five years.
Commuter services are also expected to have been running on it for three, although high-speed shuttle trains have yet to be built.
During the Games the CTRL would operate a shuttle service capable of ferrying in 25,000 people per hour from St Pancras, seven minutes away from Stratford International.
Still more would make the 10 minute journey on the CTRL from Ebbsfleet in north Kent - where there will be a special park and ride facility - and from the Continent on Eurostar trains.
And the £600M phase one of the East London Line extension and upgrade is expected to be complete. This does not run directly to the Olympic Park, but will allow passengers from south east London to get to the District and North London lines without passing through busy London Bridge station.
The project will also take passengers off the Jubilee Line.
Athletes, Olympic officials and media are not expected to travel on public transport. Instead they would travel by car or coach between the Olympic Park and athletes' village near Stratford to venues and accommodation in central London and outer London sites like the rowing lake at Eton Dorney near Windsor, the tennis courts at Wimbledon or the football final venue at the new Wembley stadium.
Their vehicles will use specially designated Olympic lanes which will form part of a 240km Olympic road network, devised by consultant Mott MacDonald working with Transport for London.
'The Olympic network is already designed and tested, ' says Transport for London's Olympic transport director Wilben Short.
These routes would also use 'green waves' - co-ordinated green traffic light sequences.
These would speed Olympic traffic travelling between the Olympic Park, central London accommodation, and other venues around the capital.
A recent dry run showed it is possible to drive from Hyde Park to the Olympic village in 21 minutes and 45 seconds, a major improvement on normal conditions.
Of the five cities shortlisted for the 2012 Games, London's bid team has come under particular pressure to produce a convincing transport strategy. London's transport infrastructure was marked down by the IOC during its initial assessments of the shortlisted cities earlier this year.
The IOC was especially critical of London's ageing and unreliable underground and commuter rail systems, and questioned the bid's seeming over-reliance on the Channel Tunnel Rail Link to deliver spectators from St Pancras using a fast shuttle service (NCE 27 May).
The transport plan has come a long way since then. 'We have taken on board the issues raised by the IOC and have carried out extensive modelling of aspects of the transport plan, ' says Short.
If anything, the IOC's concerns appear to have more to do with perception than reality. London's transport system is old and can break down, but it is denser, has more lines than most and is already receiving investment under the PPP. The bid team points out that the Olympic village site is served by 10 Tube or rail lines so there are plenty alternative routes in the system if a breakdown occurs. Other central London venues have similarly strong transport links.
In addition, the Tube and rail network operates below capacity in the summer. 'In August travel demand is down by 20% so there is ample capacity to handle the 5% increase in demand generated by the Olympics, ' says London 2012 bid team head of transport Hugh Sumner.
'London's transport system handles between 9M and 10M journeys a day. We are talking about adding another couple of hundred thousand, ' says Capita Symonds regional director, transport planning, Hedley Walker, who worked alongside engineers at Mott MacDonald on the transport plan.