LOS ANGELES - International Olympic Committee officials said Los Angeles had presented a "compelling" transportation plan for their 2024 Olympic bid on Wednesday as a crucial three-day evaluation visit got under way.

Patrick Baumann, the chairman of the IOC's Evaluation Commission, appeared to have been impressed by details of Los Angeles 2024's plans to ferry visitors around the metropolis recently ranked as the most gridlocked city in the world. "The city and the planning authorities for transportation have a very compelling case for how the transportation will be implemented for the games time period," Baumann told reporters after an opening day of discussions with the LA bid team. "They've studied this extremely carefully. We all know this is a big city but they have a compelling plan that is in line with what is required for the host of an Olympic games."

Los Angeles mayor Eric Garcetti told reporters officials had shared details of what he described as the city's "transportation revolution." This would involve $88 billion improvements and expansion to public transport infrastructure that was already under way and would be completed irrespective of whether Los Angeles wins the race to stage the Games. "We feel very confident in our ability to deliver," Garcetti said. "We were able to deliver smooth rides in 1984 and we think it will be even better in 2024."

The IOC delegation visit comes just four months ahead of a September 13 vote in Lima that will decide the race. The IOC Evaluation Commission will head to rival Paris next week. The back-to-back visits of the only two cities in the running for the 2024 Games usher in what is expected to be a frenzied final spurt of campaigning. The bidding contest has been overshadowed in recent weeks by speculation that the IOC is aiming to offer the 2028 Olympics to whomever loses out on the 2024 Games, anxious to lock in two strong bids at a time when the pool of cities willing to stage the mammoth sporting spectacular is shrinking.

Los Angeles 2024 bid chairman Casey Wasserman said he supported the IOC's move to reward both bids. "I applaud the IOC's thinking. It's the right question at the right time. But this week is about the question of why LA is the right city for 2024," Wasserman said. "We have the strongest foundations of any Olympic bid in history. The bid we submitted is the bid you will get."

The Los Angeles bid -- which enjoys 88 percent public support according to recent surveys -- has emphasized that its vision for the 2024 Games would require no new venue construction, with events staged in an array of stadia that exist or are already being built. Los Angeles officials also briefed IOC delegates on aspects of their security plan, stressing the city's experience of regularly staging entertainment showpieces such as the Oscars, Grammys and Emmys. "This was an opportunity to emphasise how safe and secure this city is," Garcetti said.

"No city has zero risk, but we do this (security) every day."

IOC delegates will on Thursday be shown an array of venues including the Los Angeles Memorial Coliseum, the centerpiece of the 1932 and 1984 Olympics held in the city. The stadium will be used once more in the 2024 Olympics for track and field, and will be used as a gigantic overflow arena in opening ceremony festivities that will be shared with the futuristic stadium being built to house the Los Angeles Rams NFL team. "We're going to show the IOC what we can spend the next seven years doing instead of pouring time, money and concrete into controversial and costly construction," Wasserman said.

Garcetti said the physical legacy of the Games would not be venues, but rather smaller projects aimed at boosting participation in sport across Los Angeles. "It's not going to be things like an Olympic village, it's going to be a new pool in your neighborhood, or a tennis court in Compton," he said.