The London Olympics, it would seem, aren't built for speed. At least not from a spectator’s perspective. Between strikes by border agents, labour stoppages by train drivers (their vehicles already suffering from suddenly soaring temperatures) and street-choking protests from cabbies upset at being squeezed out of dedicated Olympic lanes on the city's twisting, traffic-choked roads, the toing and froing of the ticket-buying public looks likely to be an enormous, time consuming challenge. Mind the gap, please, and awfully sorry about the wait. 

Still, it won't all be slow in London. Anyone lucky enough to hold a seat for the premier men's sprinting events at this Olympics (and fortunate enough to reach it on time) might well bear witness to the finest display of speed any human has ever produced.

There aren't many images from Beijing 2008 more indelible than the sight of Usain Bolt blasting his way to a world record 9.68 in the 100m final, looking around in a mix of elation and amazement as the line drew near and realized he was about to turn gold, that no one else in the world could do it anywhere as fast as him.

After that explosive entrance, it seemed less coronation than acclamation as Bolt raced to a world record 19.30 in the 200m, then joined his Jamaican teammates in setting another world record of 37.10 and claiming his third gold of the games in the 4x100m, a third chance to perform his even more indelible dancehall pose of victory, arms pointed skyward in joyous celebration.

Four years on, Bolt is expecting even bigger things from himself in London, where he will try to become the first man to successfully defend titles in both the 100m and 200m. It was with the brashness typical of a top sprinter that he was quoted in lengthy profile in The Guardian this week, shortly before Friday's Opening Ceremony. "This will be the moment," he claimed, "and this will be the year, when I set myself apart from other athletes in the world. A lot of legends, a lot of people have come before me. But this is my time."

Given what he accomplished in Beijing, it's hard to find fault with Bolt's braggadocio. No matter how he arrived in London, the lanky spinter was certain to be the most eagerly anticipated and closely examined athlete at these games.

But what makes him even more fascinating, even more watchable this time around is that he arrives, rather improbably, with something approaching an air of vulnerability. His mystique has been shattered more than once in the lead up to London, first by a false start that eliminated him from the final of last year's World Championships, and more recently by an upstart challenger within the Jamaican team ranks.

Bolt became unquestionably the biggest casualty so far of track's revised false start regulations when he arose from the blocks prematurely in Daegu, South Korea last August and was promptly disqualified. The 2009 rule change that knocks any false starter out immediately, rather than charging the first false start to the field and making any second offence a disqualification, was made to try and speed up international meets (and better fit them into TV time slots).

The disappointment of Bolt's Daegu exit, one felt by fans and sponsors as keenly as the man himself, has brought about a softening of the rules in London, with judges instructed to be lenient with body movement in the blocks as long runner's hands and feet remain planted. No one wants another high profile race affected by the officials.

The greater threat to Bolt's title defence is expected to come from The Beast. Better known as Yohan Blake, he's Bolt's fearsome but friendly rival and club teammate at home in Kingston, the man who raced to gold after Bolt was DQ'd in Daegu. The 22-year-old Blake, three years younger than his more famous countryman, beat Bolt to the tape twice in three days at Jamaica's Olympic trials less than a month ago, winning a clear victory in the 100m before pulling off a shock upset in the 200m. 

Bolt has said he welcomed those defeats, that they woke him up, left him with "eyes opened wide" and forced him to refocus. In an Aug. 5 100m final that some have speculated will the fastest ever, with all eight finalists expected to be capable of breaking the 10 second barrier, it's tempting to wonder whether Bolt's renewed energy and intensity can push him to leave a London legacy of unmatchable speed and become the first not just to defend his crown, but the first to cross the line in less than 9.5 seconds. Built for speed in London? You'd better believe it.