List of top Transportation Engineering Questions asked in GATE CE

A car is travelling at a speed of 60 km/hr on a section of a National Highway having a downward gradient of 2%. The driver of the car suddenly observes a stopped vehicle on the car path at a distance 130 m ahead, and applies brake. If the brake efficiency is 60%, coefficient of friction is 0.7, driver's reaction time is 2.5 s, and acceleration due to gravity is 9.81 m/s², the distance (in meters) required by the driver to bring the car to a safe stop lies in the range

The figure presents the trajectories of six vehicles within a time-space domain. The number in the parentheses represents unique identification of each vehicle.

The mean speed (in km/hr) of the vehicles in the entire time-space domain is ______ (rounded off to the nearest integer).

As per the International Civil Aviation Organization (ICAO), the basic runway length is increased by x (%) for every y (m) raise in elevation from the Mean Sea Level (MSL). The values of x and y, respectively, are

The following data is obtained from an axle load survey at a site:
Average rear axle load = 12000 kg
Number of commercial vehicles = 800 per day
The pavement at this site would be reconstructed over a period of 5 years from the date of survey. The design life of the reconstructed pavement is 15 years. Use the standard axle load as 8160 kg and the annual average vehicle growth rate as 4.0%. Assume that Equivalent Wheel Load Factor (EWLF) and Vehicle Damage Factor (VDF) are equal.
The cumulative standard axle (in msa) for the pavement design is _____ (rounded off to 2 decimal places).

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 $C_A$ and the capacity of Road B is $C_B$, what is $\frac{C_A}{C_B}$?

Which of the following is equal to the stopping sight distance?

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?

The vehicle count obtained in every 10 minute interval of a traffic volume survey done in peak one hour is given below. \[ \begin{array}{|c|c|} \hline \text{Time Interval (in minutes)} & \text{Vehicle Count} \\ \hline 0 - 10 & 10 \\ 10 - 20 & 11 \\ 20 - 30 & 12 \\ 30 - 40 & 15 \\ 40 - 50 & 13 \\ 50 - 60 & 11 \\ \hline \end{array} \] The peak hour factor (PHF) for 10 minute sub-interval is $\underline{\hspace{1cm}}$ (round off to one decimal place).

Consider the four points P, Q, R, and S shown in the Greenshields fundamental speed-flow diagram. Denote their corresponding traffic densities by $ k_P $, $ k_Q $, $ k_R $, and $ k_S $, 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 $\underline{\hspace{2cm}}$ s. (in integer)

A horizontal curve is to be designed in a region with limited space. Which of the following measure(s) can be used to decrease the radius of curvature?

A parabolic vertical crest curve connects two road segments with grades +1.0% and -2.0%. If a 200 m stopping sight distance is needed for a driver at a height of 1.2 m to avoid an obstacle of height 0.15 m, then the minimum curve length should be _________ \text{m}. (round off to the nearest integer)

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 _________ \text{km/h}. (in integer)

It is given that an aggregate mix has 260 grams of coarse aggregates and 240 grams of fine aggregates. The specific gravities of the coarse and fine aggregates are 2.6 and 2.4, respectively. The bulk specific gravity of the mix is 2.3. The percentage air voids in the mix is _________. (round off to the nearest integer)

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 the 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 seconds), as per the Webster’s method, is _________. (round off to the nearest integer)

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 base length of the runway at the mean sea level (MSL) is 1500 m. If the runway is located at an altitude of 300 m above the MSL, the actual length (in m) of the runway to be provided 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, $v_f$ is the free flow speed, and $k_j$ is the jam density. Assume that the speed decreases linearly with density.
Which of the following relation(s) is/are correct?

Spot speeds of vehicles observed at a point on a highway are 40, 55, 60, 65 and 80 km/h. The space-mean speed (in km/h, round off to two decimal places) of the observed vehicles is $\underline{\hspace{1cm}}$.

The longitudinal section of a runway provides the following data: \[ \begin{array}{|c|c|} \hline \text{End-to-end runway (m)} & \text{Gradient (\%)} \\ \hline 0 \text{ to } 300 & + 1.2 \\ 300 \text{ to } 600 & - 0.7 \\ 600 \text{ to } 1100 & + 0.6 \\ 1100 \text{ to } 1400 & - 0.8 \\ 1400 \text{ to } 1700 & - 1.0 \\ \hline \end{array} \] The effective gradient of the runway (in %, rounded off to two decimal places) is $\underline{\hspace{2cm}}$.

On a road, the speed – density relationship of a traffic stream is given by $ u = 70 - 0.7k $ where speed, u, is in km/h and density, k, is in veh/km. At the capacity condition, the average time headway will be:

A signalized intersection operates in two phases. The lost time is 3 seconds per phase. The maximum ratios of approach flow to saturation flow for the two phases are 0.37 and 0.40. The optimum cycle length using the Webster's method (in seconds, round off to one decimal place) is $\underline{\hspace{1cm}}$.

The shape of the most commonly designed highway vertical curve is

A highway designed for 80 km/h speed has a horizontal curve section with radius 250 m. If the design lateral friction is assumed to develop fully, the required super elevation is

In a three-phase signal system design for a four-leg intersection, the critical flow ratios for each phase are 0.18, 0.32, and 0.22. The total loss time in each of the phases is 2 s. As per Webster's formula, the optimal cycle length (in s, round off to the nearest integer) is $\underline{\hspace{1cm}}$.