| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| largest metro in the world | 1.19 | 0.3 | 5580 | 8 |
| longest metro in the world | 1 | 0.6 | 1950 | 86 |
| largest metro areas in the world | 1.57 | 0.8 | 7380 | 34 |
| largest metro systems in the world | 1.29 | 0.1 | 1010 | 3 |
| world largest metro network | 1.33 | 0.9 | 7076 | 93 |
| top 10 largest metro system in the world | 0.26 | 0.5 | 3924 | 8 |
| world's largest metro areas | 0.74 | 0.7 | 2481 | 60 |
| world's largest metro network | 1.63 | 1 | 1575 | 60 |
| 100 largest metro areas in the world | 0.63 | 0.2 | 4514 | 78 |
| longest metro line in the world | 0.06 | 0.3 | 6555 | 98 |
| world's longest metro system | 0.83 | 0.7 | 2537 | 94 |
| longest metro systems in the world | 0.98 | 0.2 | 1196 | 19 |
| world longest metro line in which country | 0.58 | 0.3 | 5132 | 98 |
| world's longest metro line | 1.68 | 0.4 | 9891 | 20 |
| longest metro network in the world | 1.66 | 0.9 | 5747 | 63 |
