Transportation industry is a service sector component, it is of important concern for the traffic engineers and planners to understand and evaluate the quality of service provided by the transport facilities. Highway Capacity Manual (HCM), quantified the concept of capacity for a transport facility and laid the foundations for estimating the level of service. This thesis is an engineering project management study; it is about evaluation and improving Two-lane highways in Jordan. This research study was conducted on three main Two-lane highways in Jordan, including: Al Salt - Al Ardha Highway, Al Salt - Wadi Shoaib Highway, Jarash - Ajloun Highway, where these highways are considered as major highways with high traffic volume in Jordan. The traffic data was collected from the government records at several departments in the Ministry of Public Work and Housing. The updated HCS 2010 programs software were used to evaluate and improve the level of service and traffic conditions at each highway for existing (year of the study-2015), short-term (2020) and mid-term (2025). The evaluation show that some segments are operating at LOS E or LOS F for existing and short-term condition. The segments that operated at LOS E or LOS F for the existing or short-term or mid-term planning were improved by modifying the geometric and traffic conditions; in order to operate on better LOS. Management flow diagrams were prepared for the decision makers to be a guide for future planning program. The results show an improvement in the performance measures where ATS and PFFS are increased and PTSF is decreased as a result an improvement in the LOS is obtained. Keywords: Highway Capacity, Highway capacity manual (HCM 2010), Two-lane Highway in Jordan, Level of Service (LOS), Highway Capacity Software (HCS 2010).