This paper presents an algorithm for the implementation of transit signal priority. The objective of this research is to develop a model to be utilised in transit signal priority systems where exclusive bus lanes are not available. Proposed model predicts the bus arrival time from an upstream bus detector to the downstream intersection. The expected waiting time of the bus at intersection is estimated using the predicted arrival time and traffic signal parameters. Different strategies, for example green extension or early green, are used based on the expected waiting time and the bus arrival time with respect to the signal cycle. The effectiveness of this model is verified using simulated data. Further, the proposed and current transit signal priority models are compared and proposed model has been found to perform significantly better than existing models.