In Dublin, Ireland we have a light tram system called the Luas. There is a green line and a red line -- they don't connect but nearly do as they are close. The

In Dublin, Ireland we have a light tram system called the Luas. There is a green line and a red line -- they don't connect but nearly do as they are close. They have different guages. It's planned that one of the lines will be upgraded to a full metro in the long term however many people think that such a fundamental descision was a simple oversight.