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Ryan B. Streff January 16, 2015 City of Arden Hills Page 3 In addition to the intersection turning movement counts, observations were completed to identify roadway characteristics within the study area (i.e. roadway geometry, posted speed limits, and traffic controls). Currently, Lexington Avenue is primarily a four-lane divided roadway with a posted speed limit of 40 miles per hour (mph), although there are segments that have a continuous center two-way left-turn lane. Red Fox Road and other study roadways are two-lane roadways with 30 mph speed limits. The Red Fox Road/Lexington Avenue intersection is signalized, while other study intersections are side-street stop controlled. It should be noted that Lexington Avenue is functionally classified as a minor arterial, while other study roadways are functionally classified as local streets. Existing geometrics, traffic controls, and volumes within the study area are shown in Figure 2. Existing Intersection Capacity Analysis An existing intersection capacity analysis was completed using Synchro/SimTraffic software (V8.0) to establish a baseline condition to which future traffic operations could be compared. Capacity 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, while LOS F indicates an intersection where demand exceeds capacity. Overall intersection LOS A though LOS D is generally considered acceptable in the Twin Cities area. 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 side-street approach. 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 side-street approaches. It is typical of intersections with higher mainline traffic volumes to experience high 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.