Rainbow Bridge (レインボーブリッジ) is a suspension bridge crossing northern Tokyo Bay between the Shibaura Wharf and the Odaiba waterfront development in Minato Ward, Tokyo. It was completed in 1993. The bridge spans 570 meters (1870 ft) and carries three transportation lines: Metropolitan Expressway No. 11 Odaiba Route on the upper deck, and Route 357 (also known as "Rinkō Dōro", Portside Avenue) and the Yurikamome New Transit on the lower deck. You can enjoy great night scene of Tokyo from this bridge.
Tourist Info.
You can access this bridge not only by car but also walking.
Open from 9:00 to 21:00 in summer, 10:00 to 18:00 in winter.
No fee.
Acess
0. at Tokyo Station
1. use JR Yamanote Line to Shinbashi (3 min.)
2. use Yurikamome Line to Shibaurafuto (7 min.)
3. walk to the bridge (5 min.)
1 hr.
New Wave Samurai Movie. 
映画好き集まれ！ 
One of the best view point for Tokyo Night scene. However, it very noisy because it is also Express way. You can enjoy all the landscape of Tokyo bay area. here.
The bridge spans 570 meters (1870 ft) and carries three transportation lines: Metropolitan Expressway No. 11 Odaiba Route on the upper deck, and Route 357 (also known as "Rinkō Dōro", Portside Avenue) and the Yurikamome New Transit on the lower deck. (Wikipedia)