On Sunday March 1st the Rainbow Bridge connecting Shibaura and Odaiba will be closed to allow the general public to walk across the bridge in a walk festival. The event is said to be in aid of:
building excitement for the sports movement aiming to bring the 2016 Olympic and Paralympic Games to Tokyo.
The official website can be found here at http://www.tokyorainbow-walk.com/ (Japanese only).
The starting time for the 7km course event is set for 8:50am. It is expected that about 5,000 people will join in the bridge walk with traffic being closed off from the bridge.
The bridge is not normally closed to traffic but there is access for pedestrians to walk alongside the cars on normal days. I have tried it and it is quite interesting with a small innovation museum in the middle section providing a welcome break for walkers. The walk access is on the lower deck of the bridge and the view is slightly stifled. This bridge walk event is different though in that you can actually walk on the top road section of the bridge and get a full view of Tokyo.
Here are the start times in detail:
平成21 年3 月1 日（日） (event on March 1, 2009)
午前7 時30 分 ～集合 (assemble from 7:30am)
午前8 時30 分 開会式 (opening ceremony at 8:30am)
午前8 時50 分 スタート (walk starts at 8:50am, expected to finish at 12:30)
Here is a map of the walking course. Note that the start point is on the Odaiba side of the bridge in the Odaiba Kaihin Koen.
Here are some great photos of the bridge from flickr: