Even India has three gauges with local/intercity trains. Narrow gauge, which is mostly used for mountainous terrain (2% of the total Indian rail network), and meter gauge (3.5% of total network) which is being converted into broad gauge (5' 6").
It's interesting that the the new Marin train[1] is standard gauge, and the connector train in Pittsburg[2] too. Amtrak in the bay area is standard guage, as is Caltrain. Bart is coming to the south bay, but I wonder if more expansions wouldn't be better off going with standard gauge. Bart transfers aren't too bad.