Compared to Bangkok Railway Station, the new Bang Sue Grand Station is massive and has platforms on multiple levels. In all, there are 24 tracks going into this station and it can accommodate 40 trains at the same time. The station covers an area of 1,280 acres and is said to be the biggest station in South-East Asia. For the railway expansion that is now taking place in Thailand, including high-speed trains to Singapore and China, it does makes sense to have somewhere big enough for these new lines.
The top floor (3rd floor) is where the high speed trains will depart from in the future. They just need to finish building the tracks for this across the country! The three-airport rail link will also depart from here in the future. This line will connect Don Mueang, Suvarnabhumi, and U-Tapao airports. The 2nd floor is for the inter-provincial trains and commuter trains. The ground floor has the ticketing offices. The car park is underground and below that is the MRT subway line.