c) Assume that traffic on a single-lane approach to a signalized intersection observes the Greenshield's speed-density relationship. The jam density on the approach is 180 veh/mile and free flow speed is 60mph. Suppose the current signal is green and the traffic is moving at 40mph and passing through the intersection. After the green time ends, the signal turns red and vehicle queue starts to build up. The signal keeps red for 60 seconds and turns green again. Answer the following questions: 1. How fast does the vehicle queue build up after the signal turns red? 2. How far the vehicles are queued in upstream, i.e. the maximum queue length?

c) Assume that traffic on a single-lane approach to a signalized intersection observes the Greenshield's speed-density relationship. The jam density on the approach is 180 veh/mile and free flow speed is 60mph. Suppose the current signal is green and the traffic is moving at 40mph and passing through the intersection. After the green time ends, the signal turns red and vehicle queue starts to build up. The signal keeps red for 60 seconds and turns green again. Answer the following questions: 1. How fast does the vehicle queue build up after the signal turns red? 2. How far the vehicles are queued in upstream, i.e. the maximum queue length?

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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An approach at a signalized intersection with a 60-second cycle gets 30 seconds of displayed green time. Yellow time is 4 seconds and all-red is 2 seconds (lost time is to be determined from standard assumptions). At the beginning of an effective red there are 4 vehicles in the queue and the saturation flow is 876 veh/h. The arrival rate is given by v(t) = 0.20 - 0.002t [with v(t) in veh/s and t in seconds after the beginning of the effective red]. What is the average vehicle delay for this approach in seconds at the end of the cycle (until the next effective red) that started with the 4 vehicles queued at the beginning of the effective red? (Assume D/D/1 queueing. Please provide you answer in decimal form without units)
7.24 Vehicles arrive at an approach to a pretimed signalized intersection. The arrival rate over the cycle is given by the function v(t) = 0.22 + 0.012t [v(t) is in veh/s and t is in seconds]. There are no vehicles in the queue when the cycle (effective red) begins. The cycle length is 60 seconds and the saturation flow rate is 3600 veh/h. Determine the effective green and red times that will allow the queue to clear exactly at the end of the cycle (the end of the effective green), and determine the total vehicle delay for this approach over the cycle (assuming D/D/1 queuing).
Traffic on a freeway gives a Greenshield's traffic flow relationship expressed as: Q = 60k-0.16667k? At 10AM, an accident occurs 4 km downstream of an access ramp. The vehicles pull onto the shoulder of the roadway, but traffic passing the accident area slows to 10 kph as drivers survey the damage on the side of the road. A patrol car enters the freeway via access ramp, also at 10AM. Upon entering the freeway, the patrol car notes that traffic on the freeway is moving along at about 40 kph. Determine the following: 1. Capacity flow of the highway 2. Traffic shockwave created by the road accident 3. Time in AM the patrol car will reach the accident zone 4. Plotted traffic shockwave line in the Q-k traffic model diagram
An observer notes that an approach to a pretimed signal, the time it will take the queue to clear after the start of the effective green (assuming that approach capacity exceeds arrivals and D/D/1 queuing applies) is 60 s. If the saturation flow rate is 1440 veh/h and the effective red time is 40 seconds, what is the maximum number of vehicles in a queue in a given cycle?
7.12 The saturation flow rate of an approach to a pretimed signal is 6000 veh/h. The signal has a 60-second cycle with 20 seconds of effective red allocated to the approach. At the beginning of an effective red (with no vehicles remaining in the queue from a previous cycle), vehicles start arriving at a rate v(t) = 0.4 +0.01t + 0.00057+² (where v(t)) is in vehicles per second and t is the number of seconds from the beginning of the cycle). 30 seconds into the cycle the arrival rate remains constant at its 30-second level and stays at that rate until the end of the cycle. What is the total vehicle delay over the cycle (in vehicle- seconds), assuming D/D/1 queuing?
Q2: What are the assumptions for using the equations in the queue test? Q3: A signalized intersection, of 105 sec cycle length, the east approach has an effective green time of 20 sec, and the percentage of vehicles arriving during green time is 28%. The west approach has 16 sec green time and 32% of vehicles arriving during the green time. Determine which approach is best coordinated with the upstream signal.
A segment of eight-lane urban freeway experiences a breakdown that blocks two lanes completely for a period of one hour in the peak direction. The breakdown occurs at 9:00 AM and is cleared by 10:00 AM. The capacity of the segment is 2,100 veh/h/In, with a maximum queue discharge rate of 1,800 veh/h/ln. Beginning at 9 AM, the traffic demand at this location is: 9:00 AM-10:00 AM 8,400 veh/h 10:00 AM-11:00 AM 8,000 veh/h 11:00 AM-12:00 Noon 7,000 veh/h After 12:00 Noon 6,000 veh/h 1. What is the maximum queue size that will form in this scenario? 2. At what time does the stable capacity value resume?
Recent computations at an approach to a pretimed-signalized intersection indicate that the volume-to-capacity ratio is 0.8, the saturation flow rate is 1600 veh/h, and the effective green time is 50 seconds. If the uniform delay is 11.25 seconds per vehicle, determine the arrival flow rate (in veh/h) and the cycle length.
An intersection has a three-phase signal with the movements allowed in each phase and corresponding analysis and saturation flow rates shown in the table below. Assume the lost time is 4 seconds per phase and a critical intersection v/c of 0.90 is desired. Phase 3 Allowed movements NB L, SB L NB T/R, SB T/R EB L, WB L EB T/R, WB T/R Analysis flow rate 330, 365 veh/h 1125, 1075 veh/h 110, 80 veh/h 250, 285 veh/h Saturation flow rate 1700, 1750 veh/h 3400, 3300 veh/h 650, 600 veh/h 1750, 1800 veh/h Using v/c equalization ratio, calculate the effective green time for phase 1 O 15.954 sec O 12.105 sec O 14.127 sec O 13.190 sec
Determine whether a T intersection (one leg on the minor approach) with the hourly volume data satisfy MUTCD Warrant 3 (peak-hr vehicular volume) for signalization. All approaches have one lane entering the intersection. For the warrant that is met, explain how the warrant is met (rules applied, hours in which the volume criteria were met, etc.) and refer to necessary graphs and tables. The major street speed limit is 60 km/h, and the minor street speed limit is 40 km/h.
A) The following traffic counts were taken on a rural highway during the morning peak hour at (9:00-10:00 am) on Saturday of a week. Time periods (minute) Number of vehicles Find: 9:00-9:30 AM 412 9:30-9:45 AM 702 9:45-10:00 AM 254 1. The hourly volume, the peak rate of flow within the hour, and the peak hour factor. 2. The daily volume for Saturday if the hourly expansion factor (HEF) is 14. B) At a highway segment, six vehicles travel the same distance of 20 miles during 21, 25, 30, 29, 31, and 25 minutes, respectively. These vehicles have stopped at a check points for about 5 minutes. Find the average running and overall travel speeds. C) A parking garage located in Misan city center opens its doors to serve 350 vehicles from 8 am to 3 pm. An analysis of data collected at the parking site indicates that these vehicles are parked for an average of 1.5 hours. If parking efficiency is 0.9, determine the number of additional spaces needs when the number of space-hours increases by 16%.
Through the Walla Walla Road to the entrance of the E-1 parking lot at the University of Washington, vehicles begin to arrive from 7:40 A.M. at a uniform deterministic rate of 480 vph until 8:20 A.M. and from then on at 120 vph. It takes 10 seconds for a vehicle to go through the paying process at the gate. If the parking lot is open at 8:00 A.M., determine (a) when the queue will dissipate, (b) the total delay, (c) the average delay, (d) the maximum queue length (in vehicles), and (e) the longest vehicle delay under FIFO. Show your results graphically. [Hint: D/D/1 analysis]