All questions of Transportation Engineering for Civil Engineering (CE) Exam

Overtaking Sight Distance:

Overtaking sight distance is the distance needed for a driver to overtake a slower vehicle safely without any risk of collision with oncoming traffic.

Formula:

Overtaking sight distance (OSD) = 0.278Vt + 0.278Vs + (Vt² - Vs²)/(254f)

Where,

Vt = speed of overtaking vehicle (kmph)
Vs = speed of slower vehicle being overtaken (kmph)
f = coefficient of friction between tire and road surface
254 = conversion factor

Given:

Vt = 100 kmph (since we need to overtake a vehicle going at 80 kmph)
Vs = 80 kmph
f = 0.35 (assumed value)

Calculation:

Substituting the values in the formula:

OSD = 0.278 x 100 + 0.278 x 80 + (100² - 80²)/(254 x 0.35)
OSD = 27.8 + 22.24 + 470.22
OSD = 520.26 m

Hence, the correct answer is option C (470 m).

Principle of Road Alignment

The principle of road alignment is an important aspect of road design and construction. It refers to the process of determining the route or path that a road will take from one point to another. The following statements explain the correct principles of road alignment.

All the Below

The correct statement is "all the below". This means that all the principles of road alignment should be followed to ensure that the road is safe, efficient, and environmentally sustainable.

Its Gradient Should be Easy

The gradient of a road refers to the slope or incline of the road. The gradient should be easy to navigate for vehicles and pedestrians. Steep gradients can cause accidents and make it difficult for vehicles to climb uphill. The gradient of a road should be carefully designed to ensure that it is easy to navigate for all road users.

It Should Aim Avoiding Deep Cuttings and Fillings

Cuttings and fillings are changes in the elevation of the land caused by road construction. Deep cuttings and fillings can cause soil erosion, landslides, and other environmental problems. To avoid these issues, road alignment should aim to minimize the depth of cuttings and fillings as much as possible.

It Should be Straight

A straight road alignment is the most efficient and direct route between two points. However, it may not always be possible to have a completely straight alignment due to terrain and environmental factors. In such cases, the road alignment should follow a gentle curve that is easy to navigate for road users.

Conclusion

The principle of road alignment is an important aspect of road design and construction. It ensures that roads are safe, efficient, and environmentally sustainable. The principles of road alignment include easy gradient, avoiding deep cuttings and fillings, and straight alignment. By following these principles, road designers and engineers can create roads that meet the needs of all road users while minimizing the impact on the environment.

Design speed and Sight distance at intersection

Design speed of a road is the maximum safe speed that can be maintained by a vehicle under ideal conditions of alignment, grade, and traffic control. Sight distance, on the other hand, is the distance that a driver can see ahead of their vehicle while driving. It is an important factor in determining the safety of a road, especially at intersections.

Relationship between design speed and sight distance

The sight distance required at an intersection depends on the design speed of the road. The higher the design speed, the greater the sight distance required, as vehicles will be traveling faster and will need more time to react to obstacles or hazards.

Calculation of sight distance at intersection

The formula used to calculate sight distance at an intersection is as follows:

Sight distance = Stopping sight distance + Passing sight distance

Stopping sight distance is the distance required for a driver to stop their vehicle, given a certain speed and a certain coefficient of friction between the tires and the road surface. Passing sight distance is the distance required for a driver to safely pass another vehicle.

For a design speed of 100 kmph, the minimum sight distance required at an intersection is 220 meters. This takes into account both stopping and passing sight distance.

Importance of adequate sight distance at intersections

Having adequate sight distance at intersections is crucial for ensuring the safety of drivers, passengers, and pedestrians. Without enough sight distance, drivers may not be able to react in time to avoid a collision or other hazard. This can lead to serious accidents and injuries.

Conclusion

Design speed and sight distance are important factors to consider when designing a road, especially at intersections. Having adequate sight distance is crucial for ensuring the safety of all road users. For a design speed of 100 kmph, the minimum sight distance required at an intersection is 220 meters.

Coefficient of Friction and its Relation to Speed

Coefficient of Friction:
The coefficient of friction is a dimensionless quantity that characterizes the frictional relationship between two surfaces. It is defined as the ratio of the force required to move one surface over another to the normal force holding them together.

Relation to Speed:
The coefficient of friction depends on the type of surfaces in contact, the roughness of the surfaces, and the speed at which they are moving relative to each other. At higher speeds, the coefficient of friction tends to decrease due to the reduced contact time between the surfaces.

IRC Recommended Value for Coefficient of Friction:

The Indian Road Congress (IRC) is a professional organization of highway engineers in India. It has published guidelines for the design and construction of highways in the country.

According to IRC guidelines, the recommended value for the coefficient of friction between tires and the road surface varies depending on the speed of the vehicle.

For a speed of about 100 kmph, the recommended value of the coefficient of friction is 0.35. This value is based on the assumption that the road surface is dry and free of oil, grease, or other contaminants.

Other Factors Affecting Coefficient of Friction:

It is important to note that the recommended value of the coefficient of friction is only an approximation and may vary depending on other factors such as:

- The type of tire and its condition
- The slope and curvature of the road
- The weather conditions (rain, snow, etc.)
- The presence of road markings or other surface irregularities

Conclusion:

In summary, the recommended value of the coefficient of friction between tires and the road surface for a speed of about 100 kmph is 0.35 according to IRC guidelines. However, this value may vary depending on other factors that affect the frictional relationship between the surfaces.

The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The shoulder joint, also known as the glenohumeral joint, is the major joint of the shoulder, but can more broadly include the acromioclavicular joint. In human anatomy, the shoulder joint comprises the part of the body where the humerus attaches to the scapula, and the head sits in the glenoid cavity. The shoulder is the group of structures in the region of the joint

Minimum Right of Way for a Village Road

The right of way (ROW) is the area of land required for the construction of a road. It is the width of land that belongs to the government and is used for the construction, maintenance, and expansion of a road. The minimum right of way required for a village road in open area is discussed below.

Factors affecting the right of way

The right of way for a village road depends upon various factors such as:

- Traffic volume
- Geometric design of the road
- Terrain
- Drainage facilities
- Roadside development

Minimum right of way for a village road

As per the Indian Road Congress (IRC) guidelines, the minimum right of way for a village road in an open area is 15 meters. However, in hilly terrain or densely populated areas, the right of way may vary from 15 to 30 meters.

Importance of a proper right of way

A proper right of way is important for the following reasons:

- It allows for the safe movement of traffic
- It provides adequate space for drainage facilities and roadside development
- It enables the expansion of the road in the future
- It helps in reducing accidents and traffic congestion

Conclusion

The minimum right of way required for a village road in open area is 15 meters. However, the right of way may vary depending upon various factors such as traffic volume, terrain, and roadside development. A proper right of way is necessary for the safe movement of traffic, adequate drainage facilities, and future expansion of the road.

In hilly terrain, the final survey requires the driving of centre line stakes at regular intervals. The correct interval between two stakes is given by option 'B', which is 20 m.

Explanation:

Centre line stakes are driven during the final survey to mark the center line of the road or any other structure. In hilly terrain, it is important to place these stakes at regular intervals to ensure that the road or structure is properly aligned and constructed.

The interval between two stakes depends on several factors such as the terrain, the length of the road, and the accuracy required. In general, the interval between two stakes should be small enough to ensure that any errors or deviations from the desired alignment can be detected and corrected.

Option 'B' suggests an interval of 20 m between two stakes. This means that a stake is driven every 20 m along the center line. This interval is suitable for hilly terrain where the slope and elevation changes frequently.

Advantages of driving center line stakes at regular intervals:

1. Ensures proper alignment: The center line stakes help to ensure that the road or structure is properly aligned and constructed.

2. Detects errors: Any errors or deviations from the desired alignment can be detected and corrected by referring to the center line stakes.

3. Accurate measurement: The regular interval between the stakes ensures accurate measurement of the road or structure.

4. Easy identification: The center line stakes make it easy to identify the center line of the road or structure during construction.

Conclusion:

The correct interval between two center line stakes in hilly terrain is 20 m. This ensures proper alignment and accurate measurement of the road or structure. The regular placement of center line stakes also helps to detect and correct any errors or deviations from the desired alignment.

Base Course of a Road

The base course is an important component of a road that provides the foundation for the pavement layer. It helps to distribute the loads from the traffic and prevent the deformation of the pavement. The base course is typically constructed with a layer of material that is strong, durable, and stable.

Broken Stone Aggregates

The correct answer for the materials used to construct the base course of a road is option 'D', broken stone aggregates. These aggregates are obtained by crushing the rocks and are available in various sizes. The size of the aggregates used for the base course depends on the thickness of the layer and the type of traffic expected on the road. The broken stone aggregates are preferred over other materials because of their superior mechanical properties.

Advantages of Broken Stone Aggregates

1. Strength - The broken stone aggregates are strong and durable, which makes them ideal for use in the base course of a road.

2. Stability - The aggregates are stable and do not deform easily, which helps to maintain the shape of the road.

3. Drainage - The broken stone aggregates have good drainage properties, which allows the water to flow through them and prevent the accumulation of water on the road.

4. Availability - The broken stone aggregates are readily available and can be obtained from local sources, which makes them cost-effective.

5. Compatibility - The broken stone aggregates are compatible with a wide range of soils and can be used in different types of soil conditions.

Conclusion

In conclusion, the base course of a road is constructed with broken stone aggregates because of their superior mechanical properties. The broken stone aggregates are strong, durable, stable, and have good drainage properties, which makes them ideal for use in the base course of a road.

Sub-arterial streets are city roads that provide access to residences, businesses, and other buildings. They are considered to be the middle-tier of streets in a city's street hierarchy, falling between arterial streets and collector streets.

Arterial Streets:
Arterial streets are the major roadways that connect different regions of a city or town. These streets are designed to handle heavy traffic volumes and are typically wider and have higher speed limits than other streets. They may also have additional features such as medians and left-turn lanes.

Collector Streets:
Collector streets are designed to collect traffic from local streets and feed it into arterial streets. They are typically narrower and have lower speed limits than arterial streets. Collector streets may also have traffic calming features such as speed humps or roundabouts to slow traffic and make them safer for pedestrians and cyclists.

Sub-Arterial Streets:
Sub-arterial streets are the streets that fall between arterial and collector streets in the street hierarchy. They are designed to provide access to residences, businesses, and other buildings, while also connecting to collector and arterial streets. Sub-arterial streets may have some traffic calming features, but they are not meant to handle heavy traffic volumes.

In summary, sub-arterial streets are important city roads that provide access to buildings and connect to other streets in a city's hierarchy. They are designed to handle moderate traffic volumes and are an essential part of a city's transportation network.

The main objective of a preliminary survey is to minimize the cost of groundwater development. Planning a preliminary groundwater survey includes minimizing the total cost of study and implementation of the groundwater development project.

Explanation:

Nagpur Road Plan:
- The Nagpur road plan was formulated in 1943 by M. Visvesvaraya to provide a comprehensive road network for the country.
- The plan takes into account the towns with a large population and aims to improve connectivity between them.
- The target road length of the plan is 16 km per 100 square km.

Second 20-Year Plan:
- The second 20-year plan was formulated in 1980 to improve the infrastructure of the country.
- The plan provided for the construction of 1600 km of expressways out of the proposed national highways.
- The plan did not allow for the deduction of the length of railway tracks in the area while calculating the length of roads.

Correct statement:
- Option C is the correct statement as it accurately describes the provision made in the second 20-year plan for the construction of 1600 km of expressways out of the proposed national highways.

Ascending Order According to Width

The ascending order according to width is as follows:

1. Carriageway
2. Formation Width
3. Right of Way

Explanation

Carriageway
The carriageway is the portion of the road that is designed for the movement of vehicles. It is the part of the road that is paved and marked with lanes for the vehicles to move on. The width of the carriageway depends on the type of road and the expected volume of traffic. It is the widest part of the road.

Formation Width
The formation width is the width of the road including the carriageway and the shoulders. The formation width also includes the drainage system, the slopes, and any other structures that are part of the road. It is the width of the road that is required to be graded and compacted to support the carriageway and the shoulders.

Right of Way
The right of way is the total width of the land that is used for the road. It includes the formation width, the drainage system, and any other structures that are part of the road. The right of way is the area of land that is acquired by the government for the construction of the road. It is the widest part of the road and includes all the land that is used for the road.

Conclusion

In conclusion, the ascending order according to width is carriageway, formation width, and right of way. The carriageway is the widest part of the road, followed by the formation width, which includes the carriageway and the shoulders. The right of way is the widest part of the road and includes all the land that is used for the road.

The final survey is an important step in the construction process to ensure that the project is built according to the design specifications. One of the tasks in the final survey is to place centre line stakes at regular intervals in plain terrain. The correct interval for placing these stakes is:

B) 100 m

Explanation:

The interval for placing centre line stakes depends on the terrain and the complexity of the project. In plain terrain, where there are no significant changes in elevation or curvature, a spacing of 100 m is considered appropriate. This spacing ensures that the stakes provide sufficient guidance for the construction crew without being too close together.

Placing the stakes at a spacing of 50 m would be too frequent and may result in confusion or errors. On the other hand, placing the stakes at a spacing of 150 m or 200 m may not provide enough guidance, leading to inaccuracies in the construction process.

Therefore, the correct interval for placing centre line stakes in plain terrain is 100 m.

Exceptional gradient in Plains

Definition:
Exceptional gradient refers to the steepness of a road or railway track. It is the ratio of vertical rise to horizontal run. The exceptional gradient is used where there is a need to climb a steep slope.

Limits on exceptional gradient:
The exceptional gradient is limited to ensure safe and comfortable transportation. In plains, the exceptional gradient is limited to 1 in 15. This means that for every 15 meters of horizontal distance, the vertical rise should not exceed one meter.

Reason for limit:
The limit on exceptional gradient is important because steep gradients can cause safety hazards and discomfort to passengers and vehicles. The following are the reasons for the limit on exceptional gradient in plains:

1. Safety: Steep gradients can cause vehicles to lose control, especially when descending. It can also cause accidents due to the difficulty of maintaining the required speed.

2. Comfort: Steep gradients can cause discomfort to passengers due to the feeling of being pushed forward or backward. It can also cause motion sickness and discomfort to passengers with medical conditions.

3. Maintenance: Steep gradients can cause wear and tear on vehicles and railways, leading to increased maintenance costs and downtime.

Therefore, the limit on exceptional gradient is necessary to ensure safe and comfortable transportation in plains.

The design of roads and highways is heavily influenced by the type and size of vehicles that will be using them. The length of the vehicle affects several design parameters, including:

Gradient:
Gradient refers to the slope of a road. Longer vehicles may have difficulty navigating steep slopes, so roads must be designed with a maximum gradient that can accommodate these vehicles.

Camber:
Camber refers to the slope of the road from the centerline to the edge. Longer vehicles may have difficulty navigating roads with a high camber, as the outer wheels may lift off the road surface. Therefore, roads must be designed with a maximum camber that can accommodate these vehicles.

Overtaking Distance:
Overtaking distance refers to the distance required for one vehicle to safely pass another vehicle. Longer vehicles require more space to safely overtake, so roads must be designed with wider lanes and ample passing zones to accommodate these vehicles.

Conclusion:
In summary, the length of a vehicle influences several design parameters for roads and highways, including gradient, camber, and overtaking distance. Road designers must consider the needs of all types of vehicles that will be using the road to ensure safe and efficient travel for all.

Stopping Distance Calculation in Vehicles

Stopping distance is the distance covered by a vehicle to come to a complete stop from a certain speed. It is an important factor in road safety as it helps drivers to maintain safe distances from other vehicles and obstacles on the road. The stopping distance of a vehicle is affected by various factors such as speed, road conditions, vehicle weight, and driver reaction time.

Height of Line of Sight of Driver and Obstacle

The height of the line of sight of the driver and obstacle on the road are crucial in calculating the stopping distance of a vehicle. The height of the line of sight of the driver is the height of the driver's eye above the road level. It is important to consider this height as the driver's visibility is limited to the line of sight. The height of the obstacle on the road is the height of the object that the driver needs to stop the vehicle for, such as a pedestrian, vehicle, or obstacle on the road.

The correct answer to the given question is option A, which states that the height of the line of sight of the driver and obstacle on the road are 1.2 m and 0.15 m, respectively. The height of the line of sight of the driver and obstacle on the road is determined based on the average height of the driver and the height of the object that needs to be avoided.

Conclusion

In conclusion, the height of the line of sight of the driver and obstacle on the road are important factors to consider while calculating the stopping distance of a vehicle. It is important to ensure that the driver's visibility is not obstructed, and the height of the obstacle is accurately measured to avoid accidents and ensure road safety.

Final Report on Road Project

The final report on road project is an important document that summarizes the key aspects of the project. It provides a comprehensive overview of the project, including the design, construction, and implementation of the road. The report should include the following:

Land Acquisition Plan

The land acquisition plan should be a detailed report that outlines the legal process involved in acquiring land for the road project. It should include information on the ownership of the land, the value of the land, and any legal issues that need to be resolved before the land can be acquired.

Cross-Drainage Details

Cross-drainage details are an essential aspect of road design. They include the design of culverts, bridges, and other structures that allow water to flow under the road. The final report should include a detailed plan for cross-drainage structures, including their location, design, and construction.

Plans of Quarries, etc.

The final report should also include plans of quarries and other sources of construction materials used in the road project. These plans should include information on the location of the quarries, the type of material extracted, and the amount of material used in the construction of the road.

Other Aspects

The final report should also include information on other aspects of the road project, such as the construction schedule, the budget, and any challenges that were encountered during the project. It should also include a summary of the project's achievements and the benefits it will provide to the community.

Conclusion

The final report on road project is an important document that summarizes the key aspects of the project. It should include a land acquisition plan, cross-drainage details, plans of quarries, and other sources of construction materials, and information on other aspects of the project. The report should provide a comprehensive overview of the project and its significance to the community.

Sight distance at intersection refers to the distance required for a driver to see and react to any potential hazards or obstacles while approaching an intersection. The minimum sight distance required depends on the speed of the vehicle and the angle of intersection. The answer is option C, which is 40 m.

Factors affecting sight distance at intersection:

1. Vehicle speed
2. Road grade
3. Horizontal alignment
4. Vertical alignment
5. Height of driver's eye and object
6. Weather conditions
7. Roadside and median obstacles

Calculation of sight distance at intersection:

Sight distance at intersection can be calculated based on the following formula:

S = (h1 + h2) / K + a

Where,
S = Sight distance
h1 = Height of driver's eye
h2 = Height of object
K = Coefficient of friction
a = Length of perception-reaction time

For intersections, the minimum sight distance required should be along the minor road. This is because drivers on the minor road are more vulnerable to accidents as they have to cross the major road. The minimum sight distance required along the minor road is 40 m, which is option C.

Conclusion:

Sight distance is an important factor in ensuring safety at intersections. It is essential to ensure that the minimum sight distance required is met to avoid accidents and ensure safe driving conditions. The minimum sight distance required at intersections should be at least 40 m along the minor road.

IRC Recommended Coefficient of Friction for Vehicle Speeds Less Than 30 kmph

IRC (Indian Roads Congress) is a governing body that formulates and recommends guidelines for road construction, design, and maintenance in India. One of the important parameters that IRC considers is the coefficient of friction, which is a measure of the grip or traction between the vehicle tires and the road surface.

The coefficient of friction is affected by various factors such as the type and condition of the road surface, the vehicle speed, the tire type, and the weather conditions. In general, a higher coefficient of friction indicates a better grip and a lower risk of skidding or slipping.

When it comes to vehicle speeds less than 30 kmph, IRC recommends a coefficient of friction of 0.25. This means that the grip between the tires and the road surface should be sufficient to ensure safe and stable movement of the vehicle at speeds up to 30 kmph.

The reason for choosing a lower coefficient of friction for lower speeds is that the braking distance and the stopping time of the vehicle are shorter at lower speeds. Therefore, the grip requirements are relatively lower compared to higher speeds where the vehicle has more momentum and requires more grip to stop or maneuver safely.

In summary, the IRC recommended coefficient of friction for vehicle speeds less than 30 kmph is 0.25. This value ensures that the vehicle has adequate grip and traction to move safely and smoothly on the road surface.