It is more than sufficient if the existing railway infrastructure is improved and the speeds improve. Moreover the punctuality of important trains is important. A daily superfast express with the average speed of 65 kmph between Visakhapatnam and chennai with stops at Anakapalli, Samalkot, Rajahmundry, Eluru, Vijayawada, Tenali, Nellore and Gudur is more than enough.