|File:Quest Subway Development.png||→||File:Quest Profitable Route.png||→|
|Subway Development||Profitable Route||Masterpiece of Engineering|
Progressive Subway is a quest chain in which the player has unlimited hours to build and upgrade a total of 2 new fixed structures with assets leading to exclusive rewards. It was released as part of an update on February 18, 2016.
|"The Subway is an ideal mode of transport for a big city – it’s fast, comfortable and there are no traffic jams! Don’t forget to keep upgrading it to keep up with technological developments!"|
|"The citizens ask the mayor to: perform modernization"|
|"Develop the Subway in Megapolis! Build new Overground Subway Stations, upgrade trains and complete profitable contracts!"|
Stage 1 - Subway Development
|You must build at least one Portland Train|
|Build an Overground Subway Station|
|80px||Accept the Short-Distance Route contract|
- Good job! Keep developing the Subway in Megapolis – it’s a profitable business!
Stage 2 - Profitable Route
|You must build at least one Amtrak Train|
|Upgrade the Overground Subway Station to Level 2|
|80px||Accept the Long-Distance Route contract|
- New routes are just what Megapolis needs! Good work, Mayor!
Stage 3 - Masterpiece of Engineering
|You must build at least one Houston Train|
|Upgrade the Overground Subway Station to Level 3|
|80px||Accept the Special Route contract|
- Brilliant! Now the Subway meets all the needs of your city. Want to tell your friends?
- Social Quantum's internal name for this quest is "Прогрессивный метрополитен" which translates to "Progressive underground".
- Social Quantum's ID for this quest is 10076097.