Traffic performance of signalized intersection is always difficult to be described by road users. They unable to plan their journey accurately if they under- or over-estimate traffic performance especially in crossing a signalized intersection. Traffic engineers who desire to overcome the problem of congestion at signalized intersection required to carry out a study before they are able to suggest any recommendations or improvements. Level of Service (LOS) is generally used for defining or describing the actual traffic performance by providing standard explanation to the road user. It is easier and simpler to be understood by the road user by categorizing the traffic performance into several levels. 1985 HCM delay model was chosen in this study to investigate and estimate the delays at signalized intersection for determining LOS. The longer the delay, the worse the LOS. Parameters such as saturation headways, saturation flow rates, loss times, actual green period and cycle time was obtained by analyzing the field data collected from the study area. All parameters were interrelated to carry out the estimation of LOS to provide a clearly defined explanation to the actual traffic performance at the study area. However, the delay model is just estimation for LOS and it may unable to fully reflect the actual condition on site. The results and conclusions obtained through this case study will be the references to evaluate the traffic performance at the signalized intersection