2017_11-28_PWETCpacket - Laserfiche WebLink

Home

2.2. Existing Roadway Capacity and Safety Roadway capacity and roadway safety are two key indicators of how well the roadway system is meeting the City's transportation needs. The sections below provide information to better understand capacity and safety issues within Roseville. 2.2.1. Existing Roadway Capacity A roadway's capacity indicates how many vehicles may use a roadway before it experiences congestion. Capacity is largely dependent upon the number of lanes and whether or not a roadway is divided. Table 1 below lists planning -level thresholds that indicate a roadway's capacity. Additional variation (more or less capacity) on an individual segment is influenced by a number of factors including: amount of access, type of access, peak hour percent of traffic, directional split of traffic, truck percent, opportunities to pass, amount of turning traffic, availability of dedicated turn lanes, parking availability, intersection spacing, signal timing and a variety of other factors. Table 1: Planning -level Urban Roadway Capacities Facilit y Type Daily Two-way Volume Lower Threshold Higher Threshold Two-lane Undivided 10,000 12,000 Two-lane Divided or Three -lane Divided 15,000 17,000 Arterials Four -lane Undivided 18,000 22,000 Four -lane Divided or Five -lane Undivided 28,000 32,000 Four -lane Freeway 60,000 80,000 Freeways Six -lane Freeway 90,000 120,000 Eight -lane Freeway or Higher Calculated on a segment -by -segment basis 2.2.2. Existing Capacity Problems on Arterial Roads At the planning level, capacity problems are identified by comparing the existing number of lanes with current traffic volumes. Table 2 and Figure 4 illustrate the existing number of lanes on arterial roadways within the City. Figure 5 illustrates existing traffic volumes on Principal Arterial, A -Minor Arterials and other significant roadways within the City. Figure 6 illustrates existing levels of service on these roadways, based on volume -to -capacity ratios. As shown in the table, I-35W/TH 36 are the only arterial roadways located within the City that have segments with more than four lanes. All other arterial roadways have four or fewer lanes. Several arterial roadways transition between the number of lanes. In some locations, these roadways have two lanes, four lanes, or three lanes (one travel lane in each direction with a center two-way left -turn lane). Several arterial roadways in Roseville are approaching or exceed the thresholds provided in Table 1, indicating existing periods of congestion on ChapterX-Transportation (DRAB) Page X-13 Adopted XXXXXXXXX XX, 2017