The Shatabdi Express which was running from 1995[5] and 2000 was stopped because it had occupancy of 60 percent as cited by Railways, It was replaced with an Intercity Express departing at identical timings.[6] Later, Indian railways introduced a Duronto Express between Chennai and Coimbatore in 2011. It was converted to Shatabdi Express on 22 Nov 2013 with commercial stoppages to increase revenues as Duronto Express should have had no commercial halt then though it could have operational/ technical halt(s) if it was needed for railways.[7][8][9][10]
By comparing with distance written on Chennai Division Map on Southern Railway website and distance written in timetable of a train having stoppages at AVADI and HINDU COLLEGE(H) on official website (If there is no reserved train having stoppages at both places, please view where schedule of unreserved trains is available on official website to verify because you don't find anything if you view the place on official website where only reserved train schedule is available.), the chargeable distance is increased by 6-7 km between AVADI and HINDU COLLEGE(H) and by comparing with distance written on Chennai Division Map and Salem Division Map both on Southern Railway website taking together, and on the other hand, distance written in timetable of a train on official website having stoppages at JOLARPETTAI and TIRUPATTUR JN (If there is no reserved train having stoppages at both places, please view where schedule of unreserved trains is available on official website to verify because you don't find anything if you view the place on official website where only reserved train schedule is available.), the chargeable distance is increased by about 4 km between JOLARPETTAI and TIRUPATTUR JN. Maybe the reason behind increasing is higher cost for special railway infrastructure of these regions (not sure). As per just mentioned Chennai Division Map and Salem Division Map both on Southern Railway website taking together, distance between MGR Chennai Central and IRUGUR(H) is 475.15 km and IRUGUR(H) to COIMBATORE JN is 17.70 km and taking their sum is 492.85 km which is real distance between MGR Chennai Central and Coimbatore but chargeable distance is 502 km. It is readers responsibility to check if following links are official or not: [1] (search maps on it) [2][3]