Ring Roads
1. Effect of newly developed ring road in Tokyo
Congestion was mitigated after the opening of the Central Circular Route in Dec. 2007
2. Comparison of ring road development among countries
Completion rate of Tokyo’s ring roads is 48%. Ring roads in the main cities in other countries are well developed with multiple lanes.
| City Planned | length | Length in service | Completion rate | note |
| Tokyo | 525km | 251km | 48% | as of Apr. 2012 |
| Beijing | 433km | 433km | 100% | Completed on Sep. 12, 2009 |
| Seoul | 168km | 168km | 100% | Completed on Dec. 28, 2007 |
| Paris | 313km | 272km | 87% | as of Jan. 2011 |
| Washington D.C. | 103km | 103km | 100% | Completed in 1998 |
| London | 188km | 188km | 100% | Completed in 1986 |
| Berlin | 223km | 217km | 97% | as of Jan. 2009 |
