The signalized analysis provided a volume to capacity (v/c) ratio for individual approaches, with a value of 1.0 representing theoretical capacity conditions and a value of 0.90 generally accepted to represent optimized conditions with full utilization of all green time.
The unsignalized intersection analysis ranks individual critical movements using a Level of Service (LOS) criteria based on average vehicle delay. Grades of “A” through “F” were assigned based on increasing delay with a LOS of “A” representing ideal, free-flow conditions, and a LOS “F” representing capacity conditions where the average delay per vehicle is greater than 50 seconds. Typically, a LOS of D would represent the point where the traffic conditions would be operating at the limit of the performance criteria for the intersection. Deterioration beyond this point would reflect the need for improvements to the intersection. However, in smaller municipalities such as Lacombe where tolerance for congestion is lower, a LOS of C would be more appropriate as the limit for performance criteria. This revised level of service rating was therefore used as a basis for analysis in this study.
The results of the capacity analysis for the study area intersections under existing conditions are summarized here in Table 4.1.
Existing traffic volumes are shown on Exhibit 4-2A (Southwest Area), Exhibit 4-2B (North Area) and Exhibit 4-2C (Southeast Area)
The results of this analysis confirmed the following regarding intersection operations within the Town:
· Locations where intersections are functional beyond the limits of their performance criteria include Highway2/58th Street for the north and southbound movements attempting to cross or turn onto the highway.
· Locations where critical movements at intersections are functioning at the limit of their performance criteria include C&E Trail/College Avenue, C&E Trail/Highway 12, 53rd Street/Highway 12, 46th Street/Highway 12, and 50th Street/Woodland Drive (eastbound and westbound only).
All other intersections are functioning well within the limits of the performance criteria.