Traffic Control and Analysis at Signalized Intersections

Traffic Control and Analysis at Signalized Intersections -...

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Traffic Control and Analysis at Signalized Intersections Intersection and signal control characteristics: Types of intersections Approach lanes and lane-groups (Figure 7.1) Types of traffic movements (left, through, right) Traffic conflict points Vehicular and pedestrian movements Signal head (lens) configurations (Figure 7.2) Signal indication (green, yellow, red) Interval Cycle Cycle length Green time Yellow time Red time All-red time Phase Protected movement Permitted movement Pre-timed Semi-actuated Fully actuated Analysis of Traffic at Signalized Intersections: Saturation Flow Rate (s): The saturation flow rate is the maximum hourly volume that can pass through an intersection, from a given lane or group of lanes, if that lane (or lanes) were allocated constant green over the course of an hour. h s 3600 Eq. 7.1 Where, s = saturation flow rate, in vph h = saturation headway, in sec/veh
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NOTE: The adjusted or prevailing saturation flow rate can also be estimated as follow: s = (s o )(N)(f w )(f HV )(f g )(f p )(f a )(f bb )(f LU )(f RT )(f LT ) Where, s = saturation flow rate for the subject lane group, expressed as a total for all lanes in lane group under prevailing conditions, in vphg s o = ideal saturation flow rate per lane, usually taken as 1900 vphgpl N = number of lanes in lane group f w = adjustment factor for lane width f HV = adjustment factor for heavy vehicles in the traffic stream f g = adjustment factor for approach grade f p = adjustment factor for the existence of parking lane adjacent to the lane group and the parking activity on the that lane f a = adjustment factor for area type f bb = adjustment factor for the blocking effect of local buses stopping within the intersection area f LU = adjustment factor for lane utilization f RT = adjustment factor for right turns in the lane group f LT = adjustment factor for left turns in the lane group Lost Time (t L ): Time that is not effectively serving any movement of traffic during a cycle. t
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This note was uploaded on 02/09/2011 for the course ECON 2250 taught by Professor Schultz during the Spring '11 term at UNO.

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Traffic Control and Analysis at Signalized Intersections -...

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