A before-and-after speed study was conducted to determine the effectiveness of a series of rumble strips installed approaching a toll plaza to reduce approach speeds to 40 mi/h. The tablebelow shows summarizes the results of the study.ItemAverageSpeedStandardDeviationSample SizeO TrueBeforeStudy43.5 mi/hⒸ False4.8 mi/h120AfterStudy40.8 mi/h5.3 mi/hAnswer the following True/False question after performing statistical analysis on the data (be sure to upload the statistical analysis solution to support your answer).The rumble strips effective in reducing average speeds to 40 mi/h. (True or False)?108

To determine whether the rumble strips were effective, we need to compare the average speed before…

A before-and-after speed study was conducted to determine the effectiveness of a series of rumble strips installed approaching a toll plaza to reduce approach speeds to 40 mi/h. The table below shows summarizes the results of the study. Item Average Speed Standard Deviation Sample Size O True Before Study 43.5 mi/h ● False 4.8 mi/h 120 After Study 40.8 mi/h 5.3 mi/h Answer the following True/False question after performing statistical analysis on the data (be sure to upload the statistical analysis solution to support your answer). The rumble strips effective in reducing average speeds to 40 mi/h. (True or False)? 108

A before-and-after speed study was conducted to determine the effectiveness of a series of rumble strips installed approaching a toll plaza to reduce approach speeds to 40 mi/h. The table below shows summarizes the results of the study. Item Average Speed Standard Deviation Sample Size O True Before Study 43.5 mi/h ● False 4.8 mi/h 120 After Study 40.8 mi/h 5.3 mi/h Answer the following True/False question after performing statistical analysis on the data (be sure to upload the statistical analysis solution to support your answer). The rumble strips effective in reducing average speeds to 40 mi/h. (True or False)? 108

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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1. A study of speed-flow-density relationships at a particular site has resulted in the following calibrated equation and graph 1:- (a) Assuming a linear relationship, derive the equations depicting the relationship between flow and density and speed and flow, for this site. (b) How long will it take for the last vehicle queued during the red phase to clear once the light turns green? Speed km/h 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 0 20 ū = 71.2 (1-122) Speed vs Density Curve 40 80 60 Density veh/km GRAPH 1 100 120 140
The municipality that controls that arterial road reduced the posted speed limit, hoping to reduce the average speed of the road to 60 km/h. After introducing the new speed limit, the municipality collected a new speed sample (sample size = 220) to calculate the operating speed. The average speed and the standard deviation of the new sample were found to be 61.09 km/h and 8.95 km/h, respectively. Based on this information, answer the following question a) Is the speed reduction (if there is any) statistically significant? b) Was the target speed achieved by introducing the new speed limit?
Assume you are an observer standing at a point along a three‐lane roadway. All vehicles in lane 1 are traveling at 30 mi/hr, all vehicles in lane 2 are traveling at 45 mi/hr, and all vehicles in lane 3 are traveling at 60 mi/hr. The spacing between vehicles in each lane is 0.5 mile. If you collect spot speed data for all vehicles as they cross your observation point for 2 hours, what will be the time‐mean speed and space‐mean speed for this traffic stream?
count peiod. n, 5, A 24-hour count using a road tube at a rural highway location produces a count of I1,250 actuations. A repre- sentative sample count to classify vehicles resulted in the data shown here: 2. en Data for Problem 2 Number of Axles Per Vehicle Number Observed 157 55 50 33 8. ---n 1EK 8 TRAFFIC DATA C Based on this sample classification count, how many vehicles were observed during the 24-hour study? 2344 6
A sample of 100 over-all travel speed was observed on a four-lane, undivided Arterial Street. The sample mean was 35.45 mph, and the standard deviation of the sample was 5.20 mph. Assume that the sample of travel speeds was taken from a normal population. a) Find the percentage of vehicles in the population traveling between 33 and 44 mph. b) Between what limits may the mean of the population be expected to fall for a 95 percent level of confidence?
A freeway traffic stream was observed to have a density of 22.0 veh/mi/ln when the mean speed was 55.0 mi/h. On another occasion at the same location, the jam density was found to be 132 veh/mi/ln. Assume Greenshields' model of traffic flow applies. The optimum speed (in mi/h) is: a) 22.0 b) 33.0 c) 55.0 d) 66.0 e) None of he above
A test of a driver’s perception/reaction time is being conducted on a special testing track with level, wet pavement and a driving speed of 50 mi/h. When the driver is sober, a stop can be made just in time to avoid hitting an object that is first visible 385 ft ahead. After a few drinks under exactly the same conditions, the driver fails to stop in time and strikes the object at a speed of 30 mi/h. Determine the driver’s perception/reaction time before and after drinking. [Assume Practical Stopping Distance].
Can someone please show me how to solve this step by step. Thank you Suppose you are hired by the UHM Transportation and Traffic Lab (TTL) to analyze vehicle arrivals at one lane of the interchange bridge connecting I-25 and I-40 for the period from 12:00am to 4:00am in a weekday. It is known that vehicle arrivals follow a Poisson process at this location. There is a single-loop detector embedded on this lane at the end of the interchange bridge. Since you do not want to go to the bridge to count vehicles at this time period, you decided to use the loop detector data for the analysis. Of the 720 20-second intervals (the loop detection system stores data every 20 seconds), 508 intervals were identified to have at least one vehicle detected. Assume the loop detector is free of error. Please estimate the vehicle arrival rate (vehicles per second) for this lane. With the estimated arrival rate, please calculate the probability of having three or more vehicles detected in a 20-second…
1 Which of these statements are always true? 1. Fully actuated signals are better than pre- timed fixed signals. 2. Traffic flow becomes random upon approaching an intersection when volume is low. 3. Traffic flow becomes random upon approaching an intersection when the distance between two intersections is significantly long enough. 4. Programs of many sets of parameters are better than a program of single set of parameters to suit different traffic flow demand.' O 1, 2 2,3 3, 4 2, 3, 4 1, 2, 3 All of 1, 2, 3, 4 None of 1, 2, 3, 4
F] Vehicles travel at constant speeds on a one-lane one-way street between sections X and Y. An observer located at point X observes the four vehicles passing point X during a period of 10 seconds. The speeds of the vehicles are measured as 45, 45, 40, and 30mph, respectively. Calculate the average flow, density, time mean speed, and space mean speed.
engineer wishing to determine the travel time and average speed along a section of an urban highway as part annual trends analysis on traffic operations conducted a travel time study using the floating -car technique .He carried out 10 runs and obtained a standard deviation of +-3 mi/h in the speeds obtained .if 5% significance level is assumed is the number of test runs adequate?
4. The statistical data of an urban spot speed study is given below. A set of 130 observations of spot speeds made by timing vehicles through a "Trap" of 88ft. The stopwatch was used to obtain data. The stopwatch data are grouped into 0.2 sec. Classes. The first column of the table shows the midpoint of each group. The second column of the table shows the frequency of the observations. Compute the following statistical values. a) The speed of each time class in mph (show it in the third column) b) The cumulative percent of vehicles traveling at or below indicated speed shown in the third column in mph (show it in the forth column) c) Mean or average speed (time-mean speed), median, mode, standard deviation, standard error of the mean, average time, space-mean speed, variance, 15%, and 85% speed. d) Plot the cumulative percentage, and show the statistical values of item (c) on the graph. e) Plot the frequency distribution curve and show the statistical values on the graph.