Slide 1

HIGHWAYS ENGINEERING

First research related to highway engineering was started in 1930, in UK.One of the first motorways of Great Britain was constructed in 1958 - the Preston bypass

Highway engineering is a branch of engineering falling under civil engineering including the planning, design, constructing, operating, and maintaining the roads, bridges, tunnels, etc. to ensure secure and efficient transportation of goods and people.Planning and DevelopmentHighway planning involves the evaluation of the current and future traffic flows on a particular road network.The requirement of safer, lesser congested and better performing highways with the growth of the economy.Improper planning, designing, construction, or maintenance of highways can cause pollution, loss of bio-diversity and natural habitat, harm to natural landscape, and the damage of a community's cultural and social structure.Safety management is an organized procedure aiming to reduce the amount and severity of road accidents.

ROAD CLASSIFICATIONFreeways: Access controlled divided highways mostly 2-4 lanes in each direction.Expressways: Superior highways designed for high speeds, high traffic volume & safety.Highways: Superior type of road networks in a country.Arterials: Meant for thorough traffic, usually divided highways with full or partial access control, with restrictions on loading, unloading and parking activities.Local Streets: Meant for access to local residential properties with unrestricted parking and pedestrian movements.Collector Streets: Meant for providing access to arterials and collection and distribution of traffic flow to & from local streets.

Speed vs. Accessibility Curve

Nagpur Road ClassificationNational Highways: main highways running through the length and breadth of India and constitute about 2% of total road networks of India.State Highways: arterial roads of a state, connecting up with the national highways constituting a total length of about 1, 37,119 Kms. Major District Roads: roads with in a district serving areas of production and markets. India has a total of 4, 70,000 kms of MDR. Other District Roads: serve rural areas of production and provide them with outlet to market centers or other important roads.Village Roads: connecting villages or group of villages with each other or to the nearest road of a higher category like ODR or MDR. India has 26, 50,000 kms of ODR+VR.

The selection of the best location, shape and alignment of ahighway is done during the design stage.Geometric Design - Highway geometric design basically means the highways visible elements. Transportation and highway engineers should not forget about the service, safety, and performance standards.Design Speed - It is defined as the highest continuous speed at which individual vehicles can travel with safety on the highway when weather conditions are favorable. Design speed is different from the legal speed limit. An 85th percentile design speed is usually adopted. This speed is defined as the speed that is greater than the speed of 85% of drivers.Topography - It refers to the study of surface shape and features of the Earth. A highway has to be successfully fit into the topography of a site and also has to be kept safe.Flexible Pavement DesignThree to four layersNatural soil subgrade is used Surface, base and subbase courses used over subgradeBase course not used in three layer pavementHot-Mix Asphalt (HMA) is used for construction

Types of overlays used:

Asphalt concrete

Portland cement concrete (PCC)

Ultra thin PCC

Rigid Pavement LayerFor constructing major highways, heavy-vehicle park or terminal pavements, heavy-duty floor slabs, port and harbor yards, etc.Built to handle modern high speed and dense trafficMostly, Portland Cement Concrete(PCC) is used for construction with steel reinforcementsTypically have life double than the flexible pavements

9Highways Drainage SystemAdequate drainage system is a must for a roadDue to excess water, premature failure can be causedDesign process is important in directing water away from the structureAnother important part is erosion controlIt is necessary that surface drainage is allowed for precipitationHighways should be built with a slope towards the drain to direct the runoff water

Requisites for proper drainage system design: Culvert designing Open channel analysis Estimation of runoff and infiltrationPavement Composition Subbase Course ConstructionLocated between the subgrade and base course of the pavementThickness: 4-16 inchesMaterials used: Gravel, crushed stone, or subgrade soil stabilized with cement, fly ash, or lime Base Course ConstructionBetween subbase and surface courseThickness: generally 4-6 inchesMaterials used: untreated crushed aggregate such as crushed stone, slag, or gravel

Portland Cement Concrete (PCC) Rigid Pavements Divided as JPCP, JRCP, CRCP Better life & expensive For holding adjacent sections, tie-bars are used.

Hot-Mix Asphalt (HMA)Flexible pavementsCheaper & lower lifePrime coat-low viscosity asphalt used on baseTack coat-bond existing pavement surface & new asphalt overlay

Highway Maintenance Main objectives of highway maintenance are:repairing the functional pavement defectsextending the functional and structural service life of the pavementmaintaining road safety and signagekeeping road reserve in acceptable condition

THANKYOUVipul Shukla3CE-1A2315813041ASET, Noida