LAB3 - Highway Capacity Manual 2000 EXAMPLE PROBLEM 1 The...

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Highway Capacity Manual 2000 Chapter 16 - Signalized Intersections 16-38 Example Problems EXAMPLE PROBLEM 1 The Intersection The intersection of Third Avenue (NB/SB) and Main Street (EB/WB) is located in the central business district (CBD) of a small urban area. Intersection geometry and flow characteristics are shown on the Input Worksheet. The Question What are the delay and peak-hour LOS of this intersection? The Facts EB and WB HV = 5 percent, Third Avenue has two lanes, one in each direction, NB and SB HV = 8 percent, Main Street has four lanes, two in each direction, PHF = 0.90, No parking at intersection, Two-phase signal, Pedestrian volume = 100 p/h, all approaches, NB-SB green = 36 s, Bicycle volume = 20 bicycles/h, all approaches, EB-WB green = 26 s, Movement lost time = 4 s, and Yellow = 4 s, Level terrain. Comments Assume crosswalk width = 10 ft for all approaches, Assume base saturation flow rate = 1,900 pc/h/ln, Assume E T = 2.0, No buses, and 70.0-s cycle length, with green times given. Steps 1. Pedestrians/cycle. 100 p h * 1h 3,600 s *70s = 1.944 p 2. Minimum effective green time required for pedestrians ( use Equation 16-2 ). G p = 3.2 + L 4.0 + 0.27N ped G p (Main) = 3.2 + 30 4.0 + 0.27(1.944) = 11.2 s G p (Third) = 3.2 + 44 4.0 + 0.27(1.944) = 14.7 s 3. Compare minimum effective green time required for pedestrians with actual effective green. G p (Main) = 26 s, which is >11.2 s G p (Third) = 36 s, which is >14.7 s 4. Proportions of left and right turns. Proportions of left- and right-turn traffic are found by dividing the appropriate turning volumes by the total lane group volume. P LT (EB) = 65 65 + 620 + 35 = 0.090 5. Lane width adjustment factor ( use Exhibit 16-7 ). f w = 1 + (W 12) 30 f w (EB) = 1 + (11 12) 30 = 0.967 6. Heavy-vehicle adjustment factor ( use Exhibit 16-7 ). f HV = 100 100 + %HV(E T 1) f HV (EB) = 100 100 + 5(2.0 = 0.952 7. Percent grade adjustment factor ( use Exhibit 16-7 ). 0% grade, f g = 1.000
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Highway Capacity Manual 2000 16-39 Chapter 16 - Signalized Intersections Example Problems 8. Parking adjustment factor ( use Exhibit 16-7 ). No parking maneuvers, f p = 1.000 9. Bus blockage adjustment factor ( use Exhibit 16-7 ). No buses stopping, f bb = 1.000 10. Area type adjustment factor ( use Exhibit 16-7 ). For CBD, f a = 0.900 11. Lane utilization adjustment factor ( use Exhibit 16-7 ). Refer to Exhibit 10-23. This factor is applied to establish the conditions in the worst lane within each lane group. Otherwise, the results would reflect the average of all lanes of the defined lane groups. Use f LU = 0.950 for EB and WB approaches, and f LU = 1.000 for NB and SB approaches. 12. Left-turn adjustment factor. The left turn is permitted, hence a special procedure is needed. The EB and WB left turns are opposed by multilane approaches. The supplemental worksheet for multilane approaches is used. The NB and SB left turns are opposed by single-lane approaches. The supplemental worksheet for a single-lane approach is used.
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This note was uploaded on 07/13/2011 for the course CME 302 taught by Professor Lin during the Fall '08 term at Ill. Chicago.

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LAB3 - Highway Capacity Manual 2000 EXAMPLE PROBLEM 1 The...

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