Concept explainers
(a)
Time mean speed.
Answer to Problem 1P
The time mean speed is
Explanation of Solution
Given:
Observers stationed at two sections XX and YY, 500 ft apart on a highway, recording the time of vehicles on their arrival as shown in the accompanying table
The total time of observation at XX was 15 sec.
In order to calculate time mean speed, we need to figure out traveling time of each vehicle which is the difference of time taken by a vehicle in travelling from XX to YY section between the two sections.
Calculation:
Vehicles | Section XX | Section YY | Travelling time of vehicle, |
A | | | |
B | | | |
C | | | |
D | | | |
We have the following formula for the time mean speed:
Where,
n is the number of the vehicles passing.
Now, the speed of the individual vehicles is as follows:
Speed of vehicle A:
Speed of vehicle B:
Speed of vehicle C:
Speed of vehicle D:
Now, the time mean speed can be calculated by substituting the values in the following formula:
Conclusion:
Therefore, the time mean speed is
(b)
Space mean speed.
Answer to Problem 1P
The time mean speed is
Explanation of Solution
Given:
Observers stationed at two sections XX and YY, 500 ft apart on a highway, recording the time of vehicles on their arrivalas shown in the accompanying table.
The total time of observation at XX was 15 sec.
Calculation:
We have the following formula for finding out the space mean speed.
Where,
Substitute the values, we have:
Conclusion:
Therefore, the time mean speed is
(c)
Flow at section XX.
Answer to Problem 1P
The flow at section XX is as follows
Explanation of Solution
Given:
Observers stationed at two sections XX and YY, 500 ft apart on a highway, recording the time of vehicles on their arrival as shown in the accompanying table.
The total time of observation at XX was 15 sec.
Calculation:
We have the following formula for finding out the flow at XX section.
Where,
Substitute the values, we have:
Conclusion:
Therefore, the flow at section XX is as follows
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Chapter 6 Solutions
Traffic and Highway Engineering
- Two sets of students are collecting traffic data at two sections, xx and yy, of a highway 1500 ft apart. Observations at xx show that five vehicles passed that section at intervals of 3, 4, 3, and 5 sec, respectively. If the speeds of the vehicles were 50, 45, 40, 35, and 30 mi/h, respectively, draw a schematic showing the locations of the vehicles 20 sec after the first vehicles passed section xx. Also, determine (a) the time mean speed, (b) the space mean speed, and (c) the density on the highway.arrow_forward1. There are 3 vehicles observed in a 100 m section of McArthur highway. If the average time headway is 4 sec., compute the space mean speed of the vehicles in kph. 2. Three cars travel over a 60 m. section of highway at constant speeds of 19, 20 and 25 m/s. Compute the time mean speed for this condition in m/s (two decimal places 3. If the density of traffic in Aurora Blvd. is 25 veh/km and the average headway is 4 sec., compute the space mean speed in kpharrow_forwardCompute the rate of flow in veh/hr if the space mean speed is 35 mph and the density of traffic is 17 veh/km a.959 veh/hr b.956 veh/hr c.957 veh/hr d.958 veh/hrarrow_forward
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- Traffic and Highway EngineeringCivil EngineeringISBN:9781305156241Author:Garber, Nicholas J.Publisher:Cengage Learning