Bus Transport is the most preferred Public Transport System in many cities. A healthy and efficient public transit system is indispensable to reduce congestion, emissions, energy consumption, and car dependency in urban areas. Recently the passenger patronage for bus transport is on the decline. Reasons reported are increased travel time, low reliability and low frequency of services in urban fringe areas. Higher dependency on private modes for travel increases the congestion level. Regular monitoring of bus operation by the operators on daily and hourly basis in terms of duration, schedule adherence is essential, as these aspects have a greater influence on passenger ridership level. Large fleet operators especially the State Transport Undertakings (STUs) in India face difficulty in monitoring the operations and are in the situation of losing passenger ridership due to declining reliability. Vehicle Tracking and Control System (VTCS) is a cost effective way of monitoring fleet of vehicles and to manage their operations. Metropolitan Transport Corporation (STU bus operator in Chennai) operates buses fitted with GPS on a busy corridor (Tambaram to Broadway) in Chennai and the bus operation along this corridor has been taken for the study. Knowledge of vehicle position time wise precisely, loading/unloading details from automatic ticketing machine has enabled to evaluate the operations of buses along the study corridor with respect to passenger loading and adherence of schedule. Variation of headway deterioration along the study corridor was analysed stretch wise using data collected from vehicle tracking system for various service types. The reasons for deterioration and its impact on passenger patronage were studied.