The high-speed train would also pass through the country’s longest tunnel of 21 km, of which seven km will be under the sea. Twelve stations have been proposed that include Mumbai, Thane, Virar, Boisar, Vapi, Bilimora, Surat, Bharuch, Vadodara, And, Ahmedabad and Sabarmati. The distance will be covered in two hours and seven minutes if the train stops at four stations — Ahmedabad, Vadodara, Surat and Mumbai. If the train stops at all 12 stations, it will cover the distance in two hours and fifty-eight minutes.