Marks 1
A single-lane highway has a traffic density of 40 vehicles km. If the time-mean speed and space-mean speed are 40 kmph and 30 kmph, respectively, the average headway (in seconds) between the vehicles is
The lane configuration with lane volumes in vehicles per hour of a four-arm signalized intersection is shown in the figure. There are only two phases: the first phase is for the East-West and the West-East through movements, and the second phase is for the North-South and South-North through movements. There are no turning movements. Assume that the saturation flow is 1800 vehicles per hour per lane for each lane and the total lost time for the first and the second phases together is 9 seconds.
The optimum cycle length (in second), as per the Webster's method, is __________. (round off to the nearest integer).
For a traffic stream, V is the space mean speed, k is the density, q is the flow. Vf is the free flow speed, and kf is the jam density. Assume that the speed decreases linearly with density.
Which of the following relations is/are correct?
Consider the four points P, Q, R and S shown in the Greenshields fundamental speed-flow diagram. Denote their corresponding traffic densities by kP, kQ, kR and kS, respectively. The correct order of these densities is :
A two-phase signalized intersection is designed with a cycle time of 100 s. The amber and red times for each phase are 4 s and 50 s, respectively. If the total lost time per phase due to start-up and clearance is 2 s, the effective green time of each phase is _________ s. (in integer)
At a traffic intersection, cars and buses arrive randomly according to independent Poisson processes at an average rate of 4 vehicles per hour and 2 vehicles per hour, respectively. The probability of observing at least 2 vehicles in 30 minutes is __________. (round off to two decimal places)
The vehicle count obtained in every 10 minute interval of a traffic volume survey done in peak one hour is given below.
| Time Interval (in minutes) | Vehicle Count |
|---|---|
| 0 - 10 | 10 |
| 10 - 20 | 11 |
| 20 - 30 | 12 |
| 30 - 40 | 15 |
| 40 - 50 | 13 |
| 50 - 60 | 11 |
The peak hour factor (PHF) for 10 minute sub-interval is _____________. (round off to one decimal place)
Marks 2
The figure presents the time-space diagram for when the traffic on a highway is suddenly stopped for a certain time and then released. Which of the following statements are true?
A plot of speed-density relationship (linear) of two roads (Road A and Road B) is shown in the figure.
If the capacity of Road A is CA and the capacity of Road B is CB, what is $\rm \frac{ C_A}{C_B }$?
Assuming that traffic on a highway obeys the Greenshields model, the speed of a shockwave between two traffic streams (P) and (Q) as shown in the schematic is __________ kmph. (in integer)
