(SEM VI) THEORY EXAMINATION 2018-19 TRANSPORTATION ENGINEERING

Transportation Engineering (RCE-603)

Complete Section-Wise Explanation – B.Tech Semester VI

Introduction to the Subject

Transportation Engineering deals with the planning, design, construction, and maintenance of transportation systems, mainly highways and pavements. This subject is extremely practical in nature and closely linked with real-world civil engineering projects such as roads, expressways, intersections, and pavements.

The paper tests:

Understanding of highway geometry

Knowledge of traffic engineering concepts

Design of horizontal and vertical curves

Pavement design (flexible and rigid)

Awareness of Indian road organizations and standards

The paper is divided into three sections: A, B, and C, and all sections must be attempted as per instructions.

SECTION A – Basic Concepts & Definitions

Pattern:
Attempt all questions
7 questions × 2 marks = 14 marks

Nature of Section A

Section A checks your basic conceptual clarity. Answers must be short, precise, and technically correct. These questions are often repeated in exams and are easy scoring if definitions are clear.

Explanation of Section A Topics

Bump Integrator:
A bump integrator is a device used to measure road roughness by recording the vertical movement of a vehicle axle as it travels over the road surface.

Skid and Slip:
Skid occurs when vehicle wheels lock and slide over the pavement surface, while slip occurs when wheels rotate faster than vehicle speed, usually during acceleration.

Road Patterns:
Road patterns refer to the layout of roads in a town or city, such as radial, grid, radial-circular, hexagonal, and linear patterns.

Summit Curve:
A summit curve is provided when two upward and downward gradients meet, mainly to ensure safe sight distance for drivers.

Possible Capacity and Basic Capacity:
Basic capacity is the maximum traffic flow under ideal conditions, whereas possible capacity considers real road and traffic conditions.

Warping and Temperature Stresses:
Warping stresses occur due to temperature difference between top and bottom of concrete slab, while temperature stresses are caused by expansion or contraction due to overall temperature change.

Tack Coat and Prime Coat:
Prime coat is applied on granular base before bituminous layer, while tack coat is applied between bituminous layers to ensure proper bonding.

 SECTION B – Design Concepts & Numericals

Pattern:
Attempt any three questions
3 × 7 marks = 21 marks

Nature of Section B

This section combines theory with numerical problems. Proper formula usage, assumptions, and step-by-step working are essential for full marks.

Explanation of Major Questions

First Twenty-Year Road Development Plan

This question focuses on Nagpur Road Plan, which laid the foundation of India’s highway development. It proposed a structured road network connecting villages, towns, and cities and aimed to improve national connectivity.

Skid Resistance & Brake Efficiency Numerical

This numerical evaluates braking performance using skid length, vehicle speed, and skid resistance. It tests understanding of vehicle-road interaction and safety.

Extra Widening on Horizontal Curve

Extra widening is provided on curves to accommodate vehicle off-tracking and psychological comfort. The question tests geometric design principles and use of standard IRC equations.

Flexible Pavement Thickness (Elastic Theory)

This numerical applies single-layer elastic theory to determine pavement thickness using wheel load, tyre pressure, modulus of elasticity, and permissible deflection.

Bituminous Surfacing Types

Sheet asphalt, mastic asphalt, and bituminous carpeting differ in composition, durability, and application. This question checks knowledge of road construction materials.

SECTION C – Design & Advanced Applications

Pattern:
Attempt one part from each question
5 × 7 marks = 35 marks

This section carries the maximum weightage and is crucial for scoring high.

Question 3 – Highway Geometry

Cross-Sectional Elements of Roads

This question explains road elements such as carriageway, shoulders, camber, median, and side drains. A neat sketch of a two-lane dual carriageway is expected.

Transition and Circular Curve Design

This numerical tests design of curves considering speed, radius, and safety. Knowledge of IRC standards is essential.

Question 4 – Highway Organizations

Highway Research Board, MORTH & IRC

This question evaluates awareness of institutional framework in Indian highway development. MORTH handles policy and execution, IRC develops standards, and research boards promote innovation.

CRF, IRC, and CRRI

These organizations support funding, standardization, and research in road construction and maintenance.

Question 5 – Gradients & Pavement Design

Minimum Gradient & Valley Curve Design

Minimum gradient ensures drainage. Valley curve design must satisfy comfort and headlight sight distance conditions, combining safety and riding comfort.

Limitations of CBR Method

CBR method has limitations such as neglect of traffic repetition and drainage. Aggregate tests like crushing, abrasion, and impact tests are also discussed.

Question 6 – Rigid Pavement & Construction

Westergaard’s Stress Analysis

This numerical calculates stresses in rigid pavement interior and edge using Westergaard’s equations. It tests understanding of rigid pavement theory.

Modern Road Construction Techniques

Bituminous macadam, SDBC, CC roads, DLC, and roller-compacted concrete roads are explained with their applications.

Question 7 – Traffic Engineering

30th Highest Hourly Traffic Volume

This concept is used in road design to represent realistic peak traffic. The rotary capacity numerical applies traffic flow principles.

Super-Elevation Design

This question tests highway safety and comfort design by calculating super-elevation as per IRC guidelines.