Gray Line
- BMT Canarsie Line
- E Embarcadero
- Gray Coach
- Gray Line Worldwide
- Grayline lascar
- Grey Line (Bangkok)
- Grey Line (Delhi Metro)
- HealthLine
- J Line (Los Angeles Metro)
- Jubilee line
- L (New York City Subway service)
- Line 6 Finch West
- Line 9 (Shenzhen Metro)
- Lynx Silver Line
- METRORapid Silver Line
- Metro (Minnesota)
- Olympic Park railway line
- Pujiang line
- S (New York City Subway service)
- Serpukhovsko-Timiryazevskaya line
- Silver Line (DART)
- Silver Line (Grand Rapids)
- Silver Line (MBTA)
- Silver Line (Mexico City)
- Silver Line (Pittsburgh)
- Silver Line (San Diego Trolley)
- Silver Line (Washington Metro)
- Terminator (solar)
- The Long Gray Line