The increasing number of road accidents year after year in India is a major concern to the government as the economic losses due to death and disabilities caused by accidents are very large. Excessive speed is one of the major causes of accidents in national and state highways and rash driving of private buses in order to maintain their schedule times lead to accidents many times. A study was carried out to analyze the speed characteristics of both private and government buses in two popular bus routes in Vellore and Tiruvannamalai districts of Tamil Nadu, namely Vellore -Arani and Vellore -Tiruvannamalai routes using handheld Global Positioning System (GPS) instruments. A total of 9 trips were collected, with six trips in private buses and three trips in government buses during morning peak hours. The analysis of GPS data revealed that in both the routes, at many stretches, private buses crosses the speed limit of 80 km/hr. However in government buses, the maximum recorded speed is only 76 km/hr. It was found that in Vellore -Arani route, the private buses recorded a maximum speed of 95 km/hr in a stretch between Pudupalayam koot road and Kunnathur. Similarly in Vellore -Tiruvannamalai route, private buses travel as high as 98 km/hr between Santhavasal and Polur. In order to adhere to the schedule times, the private buses travel at very high speeds and whenever there is a delay along the route, they make up for it by increasing their speed on the highway and this phenomenon may lead to accidents. Hence the traffic police and highways department should ensure the provision of proper speed control measures to ensure the safe journey in the routes analyzed. © IAEME Publication.