Recent questions tagged traffic-engineering

The speed-density relationship in a mid-block section of a highway follows the Greenshield’s model. If the free flow speed is $v_f$ and the jam density is $k_j$, the maxi...

A vehicle is moving on a road of grade $+4 \%$ at a speed of $20 \: m/s$. Consider the coefficient of rolling friction as $0.46$ and acceleration due to gravity as $10 \:...

The uniform arrival and uniform service rates observed on an approach road to a signalized intersection are $20$ and $50$ vehicles/minute, respectively. For this signal, ...

If the total number of commercial vehicles per day ranges from $3000$ to $6000$, the minimum percentage of commercial traffic to be surveyed for axle load is$15$$20$$25$$...

The critical flow ratios for a three-phase signal are found to be $0.30, 0.25$ and $0.25$. The total time lost in the cycle is $10 \: s$. Pedestrian crossings at this jun...

A motorist traveling at $100$ km/h on a highway needs to take the next exit, which has a speed limit of $50$ km/h. The section of the roadway before the ramp entry has a ...

In a one-lane one-way homogeneous traffic stream, the observed average headway is $3.0$ s. The flow (expressed in vehicles/hr) in this traffic stream is ________

While traveling along and against the traffic stream, a moving observer measured the relative flows as $50$ vehicles/hr and $200$ vehicles/hr, respectively. The average s...

Vehicles arriving at an intersection from one of the approach roads follow the Poisson distribution. The mean rate of arrival is $900$ vehicles per hour. If a gap is defi...

The queue length (in number of vehicles) versus time (in seconds) plot for an approach to a signalized intersection with the cycle length of $96$ seconds is shown in the ...

The radius of a horizontal circular curve on a highway is $120$ m. The design speed is $60$ km/hour, and the design coefficient of lateral friction between the tyre and r...

A superspeedway in New Delhi has among the highest super-elevation rates of any track on the Indian Grand Prix circuit. The track requires drivers to negotiate turns with...

The following statements are made related to the lengths of turning lanes at signalised intersections:$1.5$ times the average number of vehicles (by vehicle type) that wo...

The relation between speed $u$ (in km/h) and density $k$ (number of vehicles/km) for a traffic stream on a road is $u=70-0.7k$. The capacity on this road is _________ vph...

Which of the following statements CANNOT be used to describe free flow speed $(u_f)$ of a traffic stream?$(u_f)$ is the speed when flow is negligible$(u_f)$ is the speed ...

The acceleration-time relationship for a vehicle subjected to non-uniform acceleration is,$$\dfrac{dv}{dt} = (\alpha\: – \beta v_0) e^{ - \beta t}$$where, $v$ is the spee...

On a circular curve, the rate of superelevation is $e$. While negotiating the curve a vehicle comes to a stop. It is seen that the stopped vehicle does not slide inwards ...

A sign is required to be put up asking drivers to slow down to $30$ km/h before entering Zone $Y$ (see figure). On this road, vehicles require $174$ m to slow down to $30...

A student riding a bicycle on a $5$ km one-way street takes $40$ minutes to reach home. The student stopped for $15$ minutes during this ride. $60$ vehicles overtook the ...

A pre-timed four phase signal has critical lane flow rate for the first three phases as $200$, $187$ and $210$ veh/hr with saturation flow rate of $1800$ veh/hr/lane for ...

The chainage of the intersection point of two straight is $1585.60$ m and the angle of intersection is $140^{\circ}$. If the radius of a circular curve is $600.00$ m, the...

The average spacing between vehicles in a traffic stream is $50$ m, then the density (in veh/km) of the stream is _______

An isolated three-phase traffic signal is designed by Webster’s method. The critical flow ratios for three phases are $0.20$, $0.30$, and $0.25$ respectively, and lost ti...

A traffic survey conducted on a road yields an average daily traffic count of $5000$ vehicles. The axle load distribution on the same road is given in the following table...

The speed-density $(u-k)$ relationship on a single lane road with unidirectional flow is $u=70-0.77k$, where $u$ is in km/hr and $k$ is in veh/km. The capacity of the roa...

A traffic office imposes on an average $5$ number of penalties daily on traffic violators. Assume that the number of penalties on different days is independent and follow...

The minimum value of $15$ minute peak hour factor on a section of a road is$0.10$$0.20$$0.25$$0.33$

A pavement designer has arrived at a design traffic of $100$ million standard axles for a newly developing national highway as per $IRC:37$ guidelines using the following...

A two-lane urban road with one-way traffic has a maximum capacity of $1800$ vehicles/hour. Under the jam condition, the average length occupied by the vehicles is $5.0 \:...

Two major roads with two lanes each are crossing in an urban area to form an un-controlled intersection. The number of conflict points when both roads are one-way is “X” ...

The space mean speed (kmph) and density (vehicles/km) of a traffic stream are linearly related. The free flow speed and jam density are $80$ kmph and $100$ vehicles/km re...

A car follows a slow moving truck (travelling at a speed of $10$ m/s) on a two-lane two-way highway. The car reduces its speed to $10$ m/s and follows the truck maintaini...

Peak Hour Factor (PHF) is used to represent the proportion of peak sub-hourly traffic flow within the peak hour. If $15$-minute sub-hours are considered, the theoreticall...

There are $20,000$ vehicles operating in a city with an average annual travel of $12,000$ km per vehicle. The NOx emission rate is $2.0$ g/km per vehicle. The total annua...

A well-designed signalized intersection is one in which thecrossing conflicts are increasedtotal delay is minimizedcycle time is equal to the sum of red and green times i...