This paper examines the impact of vehicle types – cars, buses، and trucks - on traffic capacity in one direction on a road. To conduct a study on the impact of vehicle types، a manual traffic count was conducted at a specific time (from 12:00 to 1:00 p.m.) in one direction along a specific section of the coastal road in Khoms. All vehicle types were recorded in a table, and the percentage of each type of traffic within the total number was calculated. Traffic capacity was adjusted based on the presence of buses and trucks, road familiarity, and the terrain. The traffic capacity is estimated at 2,000 private vehicles per hour per lane, provided that standard conditions are met: all vehicles must be private، the lane width must be at least 3.65 m, the shoulder width must be at least 1.8 m, the drivers must be familiar with the road, and the terrain must be flat. The results showed that the actual traffic capacity, after correcting for the parameters, is equal to (1,900 private vehicles/hour/lane) less than the standard traffic capacity. This is due to the passage of various types of motor vehicles, including cars, buses, and trucks. The lower traffic capacity than the standard value is explained by the change in the traffic composition, as the presence of buses and trucks negatively affects traffic flow and reduces the standard traffic capacity of the road................. Keywords:.... Road, One-way, Traffic capacity, Traffic, Vehicle types.