Impact of Side Frictions on Traffic Flow and Service Quality in Karbala Streets

The increase in side friction (SF) in many urban roads led to an increase in the volume of traffic in many road networks, especially on Al-Tarbia Street and Al-Abbas Street in the city of Karbala. On these roads, many public facilities were established, which led to an increase in some activities on the sides and along the road, which effect on the road capacity and reduce it. The aims of this research to know the side friction and the level of service for each segment of the road and to know the extent of the impact of (SF) on the level of service using the Indonesian Highway Capacity Manual (IHCM1995) and the Highway Capacity Manual (HCM2010). The survey was conducted for several days, from 7:30-9:30 in the morning and 12:00-2:00 in the evening. The data obtained for each segment of the selected roads at a distance of 150 meters are engineering data, traffic data, and lateral friction data. The results showed that the highest flow rate occurred during the morning peak hours for the first segment of Al-Abbas Street and the second segment of Al-Tarbia Street, and all the lateral friction values were very high, and the level of service ranged between (B, F) in all sections. © 2025 Elsevier B.V., All rights reserved.