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Marc Culver, PE City of Roseville Intersection Capacity Analysis February 12, 2015 Page 6 An operations analysis was conducted to determine how traffic will operate at the study intersections under existing conditions. All intersections were analyzed using Synchro/SimTraffic software and the Highway Capacity Manual (HCM). Intersection operations analysis results identify a Level of Service (LOS) which indicates how well an intersection is operating. Intersections are ranked from LOS A through LOS F. The LOS results are based on average delay per vehicle, which correspond to the delay threshold values shown in Table 1. LOS A indicates the best traffic operation and LOS F indicates an intersection where demand exceeds capacity. Overall intersection LOS A through D is considered to be acceptable traffic flow conditions based on MnDOT guidelines. Table 1. Level of Service Criteria for Signalized and Unsignalized Intersections LOS Designation Signalized Intersection Average Delay/Vehicle (seconds) Unsignalized Intersection Average Delay/Vehicle (seconds) A < 10 < 10 B >10-20 >10-15 C >20-35 >15-25 D >35-55 >25-35 E >55-80 >35-50 F > 80 > 50 For side -street stop controlled intersections, special emphasis is given to providing an estimate for the level of service of the minor approaches. Traffic operations at an unsignalized intersection with side -street stop control can be described in two ways. First, consideration is given to the overall intersection level of service. This takes into account the total number of vehicles entering the intersection and the capability of the intersection to support these volumes. Second, it is important to consider the delay on the minor approach. Since the mainline does not have to stop, the majority of delay is attributed to the minor approaches. It is typical of intersections with higher mainline traffic volumes to experience increased levels of delay (i.e. poor levels of service) on the side -street approaches, but an acceptable overall intersection level of service during peak hour conditions. Results of the existing operations analysis shown in Table 2 indicate that all study intersections currently operate at an acceptable overall LOS D or better during the p.m. peak hour with the existing geometric layout and traffic control, except along County Road C at the Lincoln Drive and Snelling Avenue intersections, which operate at LOS F.