Having a subway or a train system in Bahrain, is a very good question to be brought up, due to the heavy traffic that is increasing year by year. But the answer to it is when, where and how, is it sufficient to built a subway system or train system. In my opinion a train system would cost less at the moment but depending on the gov't expenditure and how much they are willing to pay. But as you know these days everything seems in a way possible one way or the other.
Looking at a subway, which is a rapid transit either underground level or above ground level. In larger metropolitan areas the underground system may extend only to the limits of the central city, or to its inner ring of suburbs, with trains making relatively frequent station stops. So, for Bahrain I don't think it would be that much of a problem, if they do it in the accurate and precise way which Bahrain is known for when accomplishing gov't projects.
An enlargeable map of the Kingdom of Bahrain
Bahrain fountain.
1945 Boston Rapid Transit Proposed ExtensionsIf this project will actually be presented to the kingdom it will cut down the traffic tremendously and not only that but also it will be greatly environmentally friendly with pollution dropping more than 50 percent. The Kingdom will benefit not only in transport and environment but in many other ways too. The People will be less stressed out while driving early in the morning and late at night. Annual accidents will drop, leading to insurance drops, the only disadvantage to my knowledge is the automotive rental transport that will be affected, like taxi and buses, other than that maybe the structural building is not completely safe but still they can find a way but the sooner they develop this project the quicker and less expensive it...