Transportation Engineering PDF

# Transportation Engineering ## Introduction - Transportation Engineering is a branch of civil engineering involved in planning, design, operation, and maintenance of safe and efficient transportation systems. - These systems include: - Roadways - Railways - Waterways - Intermodal...

# Transportation Engineering ## Introduction - Transportation Engineering is a branch of civil engineering involved in planning, design, operation, and maintenance of safe and efficient transportation systems. - These systems include: - Roadways - Railways - Waterways - Intermodal Operations ## Need of Transportation System - Transportation engineers work to ensure the safe, economical, and timely movement of people and goods. - Transportation engineers are involved in all aspects of new private and public transportation projects. - Transportation engineers address concerns such as: - Energy needs - Budget constraints - Environmental concerns ## Importance of Transportation Engineering - The advancement of transportation facilities has been closely linked with the development of human beings. - The economic status of any country depends upon the efficiency of its transportation systems. - All agricultural and industrial products require transportation for various stages from production to distribution. ## Scope of Transportation Engineering - Engineers specializing in transportation engineering are needed by construction companies to prepare: - Preliminary and final plans - Plans for highways - Plans for bridges - Drainage structure plans - Municipal utility plans - Roadway lighting plans - Traffic control devices - Intelligent transportation systems ## Historical Development of Roads ### Early Development - The oldest mode of travel was on footpaths. - Animals were also used to transport men and materials. - Simple, animal drawn vehicles were developed and became a popular mode of transportation after the invention of the wheel. - This required the development of a hard surface for vehicles to move on. - Such a hard surface is believed to have existed around 3500 B.C. ### Roman Roads (312 B.C.) - Roman Roads were made of an earthed road with a graveled surface. - Roman Roads were constructed straight without any gradient. - The soft soil on top was removed till a sturdy layer of earth was reached. - The total thickness of the road section was 750–1200 mm. - **Construction of Roman Roads:** - A diagram is included depicting the sections of a Roman road. - The sections include a kerbstone, lime concrete, broken stones in lime concrete, foundation stones in lime mortar, and a subgrade. - The total thickness of the road was 0.75–1.2m. ### French Roads or Tresaguet Roads (1716-1796) - The next major development in road construction occurred during Napoleon's rule. - 200 mm pieces of stone with a compact form were used to build roads. - Smaller pieces of broken stones were compacted into the spaces between larger ones to provide a level surface. - The running layer was made with a layer of 25 mm sized broken stone. - **Construction of French Roads:** - A diagram is included depicting the sections of a French road. - The sections include a sloping wearing surface, foundation stones, and broken stones. - The total width of the road was 2.7 m. ### Telford Construction (1757-1834) - The foundation was prepared for a road with a width of 9 m. - Large size stones of width equal to 40 mm and depth 170 to 220 mm were laid. - After filling the spaces between foundation stones, two layers of stone were added having thicknesses of 100 mm and 50 mm. - The top layer of road was made of a 40 mm thick layer of gravel. - **Construction of Telford Roads:** - A diagram is included depicting the sections of a Telford road. - The sections include a flat subgrade, foundation stones, a layer of broken stones and gravel, and a layer of gravel. - The total width of the road was 365 mm. ### British or Macadam Roads (1756-1836) - The British engineer John Macadam introduced the first scientific road construction method. - Stone size was an important element of Macadam roads. - John Macadam observed that 250 mm thick layers of compacted broken angular stone would provide the same strength and stiffness as a pavement using expensive stones. - This was a more economical method of road construction. - **Construction of Macadam Roads** - A diagram is included depicting the sections of a Macadam road. - The sections include a compacted subgrade, a layer of broken stones, and a surface course. - The total width of the road was 4.5 m. ## Difference Between Telford and Macadam Construction | Parameter | Telford | Macadam | |--------------------------|------------------------|-----------------------| | Subgrade slope | Horizontal | 1 in 36 | | Foundation stone | 170–220 mm | 50–100 mm | | Base course | Two layers of broken stones | One layer of broken stone | | Surface course | 40 mm thick with slope 1 in 45 | 50 mm thick with slope 1 in 36 | | Thickness of cross section | 410 mm at center, 350 at edge | 250 mm only. | ## Modes of Transportation ### Land Ways Transportation - Land transport is the transport or movement of people, animals, or goods from one location to another. - The two main forms of land transport are rail transport and road transport. ### Roadways Transportation - Road transport means the transportation of goods and personnel using roads. - Roads are defined as a route that enables transportation by motorized and non-motorized carriages. - **Advantages:** - Flexible Service - Door-to-Door Service - Cheapest for shorter distances - Easy to Monitor - **Disadvantages:** - Vulnerable to congestion and traffic delays - Affected by weather - Dependence on fuel prices - Needs an extensive road network and proper area ### Railways Transportation - Rail transport is the conveyance of passengers and goods using wheeled vehicles on railways. - Rail transport is rapid, energy-efficient, but capital-intensive. - Rail transport is an important part of the logistics chain that facilitates international trade and economic growth. - **Advantages:** - Safe mode of transport - Most effective when connected with multimodal transport - Lowest overall cost per unit weight - Supports environmental protection - **Disadvantages:** - Fixed route - Can not be stopped at intermediate points - Can not provide door-to-door service - Inflexible ### Multimodal Transport - Multimodal transport (also known as combined transport) is the transportation of goods using more than one mode of transport. - The carrier is legally liable for the entire journey. - Multimodal transport commonly utilizes rail, sea, and road transport. - **Advantages:** - Lowest cost as compared to other modes - Can carry up to 500,000 DWT loads - Most suitable for long haul and low cost commodities - **Disadvantages:** - Slowest speed as compared to other modes - Accessibility and frequency may vary - Dependence on road for last mile connectivity ### Pipeline Transportation - Pipeline transport is the transportation of goods or material through pipes. - Pipelines are used to transport liquids and gases as well as any chemically stable substance. - Pipelines commonly transport crude and refined petroleum, fuels such as oil, natural gas and biofuels, and other fluids that may include sewage, slurry, water, and beer. - **Advantages:** - Suitable for all weather - Low energy consumption - Space utilization - Continuous - **Disadvantages:** - State of commodity to be transported is limited - Leakages - High fixed costs - Inflexible ### Airways Transportation - Air transport is one of the fastest modes of public transportation. - Air transport connects international boundaries and allows international travel. - Air transport is used for: - Personal purposes - Business purposes - Medical purposes - Tourism purposes - **Advantages:** - Flexible - Quick Service - Natural highways - Protection - High Speed - **Disadvantages:** - High cost of construction and maintenance - Costliest - Limited carrying capacity - International restrictions - Unsuitable for bulky goods ### Waterways Transportation - Water transport utilizes waterways for moving watercraft such as barges, boats, ships, or sailboats. - Waterways include bodies of water such as seas, oceans, lakes, canals, and rivers. - The dominant aspect of watercraft construction and maintenance is the development of the hull. - Ship transport is primarily used for the carriage of people and non-perishable goods. - **Advantages:** - Cheapest mode of transport - Large carrying capacity - Safety - Protection to goods - Flexibility - **Disadvantages:** - Slow - Huge capital expenditure - High cost of maintenance - No door-to-door service - Special packing ## Highway Development and Planning ### Classification of Roads - **Classification of roads is done on the following bases:** - Traffic - Transport tonnage - Importance - Location and function - Materials ### According to Traffic | Sr.No. | Types of Road | Vehide Per Day | |--------|-----------------------|-------------------| | 1 | Very Heavytraffic Road | Above 600 | | 2 | Heavy traffic Road | 251 to 600 | | 3 | Medium traffic Road | 70 to 250 | | 4 | Light traffic Road | Below 70 | ### According to Transport Tonnage | Sr.No. | TypesofRoa | Vehide Per Day | |--------|-------------------------|-------------------| | 1 | Very Heavytraffic Road | Above 1524 | | 2 | Heavy traffic Road | 1017 to 1524 | | 3 | Medium traffic Road | 508 to 1017 | | 4 | Light traffic Road | Below 508 | ### According to Importance - Class I - Class II - Class III ### According to Importance - Earthen Road - Water-Bound Macadam Road - Bituminous Road - Cement-Concrete Road ### According to Location and Function - National Highway (NH) - State Highway (SH) - Major District Roads (MDR) - Other District Roads (ODR) - Village Roads (VR) ### National Highway (NH) - National highways run throughout India. - National highways connect major ports, foreign highways, capitals of large states. - National highways also connect large industrial and tourist centers. - They are critical for strategic movement and the defense of India. ### State Highway (SH) - State highways are arterial roads that connect national highways and district roads. - State highways are also essential for connecting cities and districts. - State highways and national highways have the same design speed and geometric specifications. ### Major District Roads (MDR) - Major District Roads are important roads within a district. - They connect areas of production and markets to major highways. - Major District Roads have lower design specifications than State Highways. ### Other District Roads (ODR) - Other District Roads provide rural areas of production with access to markets. - Road networks connect to district headquarters and other main roads. - Other District Roads have lower design specifications than Major District Roads. ### Village Roads (VR) - Village Roads connect villages or groups of villages. - Village Road networks connect villages to nearby roads of a higher category such as those belonging to district networks. ### Classification of Highways based on the Modified System - **Primary:** - Expressways - National Highways - **Secondary:** - State Highways (SH) - Major District Roads (MDR) - **Tertiary:** - Other District Roads (ODR) - Village Roads (VR) ### Expressways - Expressways are designed for heavy traffic at high speeds (120 km/hr). - The land width is 90 m. - Access to expressways is restriced with full access controls in place. - Expressways connect major points of traffic generation. - No slow moving traffic is allowed on expressways. - Loading, unloading, and parking are prohibited. ### Urban Roads - **Arterial Roads** - No frontage access - No standing vehicles - Very little cross traffic - Design Speed: 80km/hr - Land width: 50-60 m - Divided roads with full or partial parking - Pedestrian access allowed at intersections only - **Sub-Arterial Roads** - Bus stops but no standing vehicles - Less mobility than arterial roads. - Spacing for Central Business Districts (CBD) is 0.5 km - Design speed: 60 km/hr - Land width: 30–40 m - **Collector Street** - Collects and distributes traffic from local streets. - Provides access to arterial roads. - Located in residential, business, and industrial areas. - Full access is allowed. - Parking is permitted. - Design speed: 50 km/hr - Land Width: 20–30 m - **Local Street** - Design Speed: 30 km/hr. - Land Width: 10–20 m. - Primary access to residences, businesses, or other abutting properties. - Lower volume of traffic with slow speeds. - Unrestricted parking, pedestrian movements, and no waiting restrictions. - **Cul-De-Sac** - A dead-end street with only one entry point that serves as both an entrance and exit. - Recommended for residential areas. - **Driveway** - Private roads for local access to properties. - Driveways are owned and maintained by individuals or groups. - Driveways commonly serve as paths to private garages, fuel stations, or houses. ### Road Patterns - **1. Rectangular or Block Pattern:** - The area is divided into rectangular segments having a common business area. - A diagram is included depicting a grid pattern and a map of Chandigarh. - **Advantages:** - Easier to construct and maintain. - **Limitations:** - Not very convenient from a traffic standpoint. - **2. Hexagonal Pattern:** - A network of roads is formed that uses hexagonal shapes. - At each corner of a hexagonal area, three roads meet. - A diagram is included showing a hexagonal pattern. - **Advantages:** - Three roads meet the built-up area boundary. - **Limitations:** - Requires adequate traffic signs, pavement markings, and lighting to make drivers aware of the need for reduced speeds. - **3. Radial or Star and Block Pattern:** - A network of radial roads that emanate from the business area. - The area between radiating roads may be planned with rectangular blocks. - A diagram is included depicting a radial pattern. - **Advantages:** - Reduces the level of congestion at the primary bottleneck locations. - Prevents direct traffic flow to local areas in case of a large event. - Allows for traffic flow in both directions if one block is closed. - Vehicles face each other less often than with rectangular patterns. - **Limitations:** - Less effective for two-lane roads where ramp traffic must merge. - Safety features such as guide rail transitions, crash attenuators, and post support bases are not always designed to provide adequate protection. - **4. Star and Circular Pattern:** - A network of radial roads radiating from the central business district. - Concentric roads are incorporated into the network. - The built-up area has a curved block system. - A diagram is included depicting a combination radial / circular pattern as well as a map of Connaught Place in New Delhi. - **Advantages:** - Traffic flows radially and avoids the central business area. - Reduces congestion in the center of the city. - Well suited for large cities. - **5. Star and Grid Pattern:** - A network of radial roads arranged in a grid pattern. - A diagram is included depicting a combination radial / grid pattern. - **Advantages:** - Keeps vehicular traffic safe. - Reduces cut-through traffic. - Improves traffic flow in both directions. - Improves land use efficiency and unit density. - **Limitations:** - Islands separating the approach and exit lanes need to be sufficiently large enough to be effective. - Needs adequate traffic signs, pavement markings, and lighting to make drivers aware of the need for reduced speeds.