Estimating delays at different road segments and intersections is a primary step in any traffic management system. Delay along a path can be estimated using sensors such as Global Positioning System (GPS) sensors, Camera sensors, Wi-Fi sensors and On-Board Diagnostics (OBD) data of the vehicle. The former three techniques have been used for some time now, but the latter one has not been explored much, especially for estimating delay. The accuracy of methodologies using OBD, Wi-Fi and Camera was calculated using data from GPS as ground truth. Results obtained showed the performance of all these methods to be comparable. Choice of the right sensor may depend on various other factors such as cost, weather factors, accuracy, range, etc. Sometimes more than one sensor needs to be used for the desired results. This paper explores three techniques in more detail and summarizes the advantages and disadvantages of each one of them in various scenarios.