Highway Capacity | Definition, Types & Factors
It is the ability of a road to accommodate traffic volume. It is the maximum hourly rate at which vehicles can reasonably be expected to cross a point on a roadway during a given time period under prevailing traffic roadway and control condition. For multi lane highway it is 2000pcphpl,
Definition, Advantages & Disadvantages of Freeways
A freeway or corridor is a long stretch of road connecting various large and small streets intersecting it at various spots. They provide a non stop, comfortable and an easy access to the road users without delays and with less vehicular fuel costs with the presence of grade separated junctions including flyovers and underpasses. Freeways and corridors are free ofFree Flow Speed of a Vehicle
Free-flow-speed of a vehicle is defined as: The desired speed of drivers in low volume conditions and in the absence of traffic control devices. The mean speed of passenger cars that can be maintained in low to moderate flow rates on a uniform freeway segment under prevailing roadway and traffic conditions. Factors affecting free flow speed: Width, Lateral clearance,
California Bearing Ratio Test Procedure and Test Report
It is the ratio of force per unit area required to penetrate a soil mass with standard circular piston at the rate of 1.25 mm/min. to that required for the corresponding penetration of a standard material. The California Bearing Ratio Test (CBR Test) is a penetration test developed by
Components of Road Structure | Methods of Construction of Road Structure
1. Subgrade is the foundation of the road, thus its the lowest and most important component of road structure. 2. SUB BASE Consists of a. Upper Base Courseb. Sub or Lower Base Course... If natural surface is above the formation level then the surface is cut down to proposed sub grade surface If natural surface is below the formation level then the sub grade will be above theTraffic Load - Definition and Analysis
This is the role of the Pavement Engineer and involves determining the loading on the road to be carried forward to the Pavement Design. The role of the pavement engineer is to provide an adequate thickness of pavement to carry the expected loads without deterioration of the network during the design life. The estimated or projected magnitude and occurrence of
Highway Drainage Design, Structures and Guidelines
Includes collecting, transporting, and disposing of surface/subsurface water originating on or near the highway right of way or flowing in streams crossing bordering that right of way. Drainage of highway is important because water damage highway structure in many ways. The water which are dangerous for highways are: Rainwater: Cause erosion on surface or may
Types of Pavements - Flexible Pavement / Rigid Pavement
Flexible pavements are those pavements which reflect the deformation of subgrade and the subsequent layers to the surface. Flexible, usually asphalt, is laid with no reinforcement or with a specialized fabric reinforcement that permits limited flow or re positioning of the roadbed under ground changes. The design of flexible pavement is based on loadCauses of Roadway/Highway Failure
Pavement considered flexible and the failure mechanism is assumed to be plastic deformation due to the communicative load over the life of pavement. Elastic Deformation: Temporary deforms the foundation material and compresses the air that fills the voids of the base and subgrade. In truly elastic deflection, permanent unevenness does not occur, even under repeated
Design & Construction of Culverts
An opening through an embankment for the conveyance of water by mean of pipe or an enclosed channel. Generally selection and type of material depends on the comparative cost, location of structure, availability of skilled labor, time limitations.
Typical Road Structure Details - Road Composition
The design should be done so that to meet the above requirements for considerable number of years (need proper design and construction supervision). Pavement meeting all the requirements above have been product if six distinctly different construction processes as follows. Heat a viscous bituminous binder to make it fluid, then in a plant mix it with heated
Typical Cross Section of Roads and Highways
In meeting oncoming vehicle or passing slower ones, the portion selected by a driver depends primarily on the paved surfaced width of the highway. The width of the surfaced road and the no of lanes should are adequate to accommodate the type and volume of traffic anticipated and the assumed design speed of vehicles.
Geometric Design of Highways and Roads
The geometric design of highway includes the principle elements of highway alignment, x-sections and adjacent road side environment. The three dimensional physical location determined through calculation of horizontal and vertical alignment of highway centerline, based on variety of operational considerations results in the geometric design and represent all
Factors Affecting Selection of Highway Location
Traffic planner from various studies can predict the effect of travel patterns of alternative location proposed highway. Also they analyze the probable effect of new links in highway network. This permits the location engineer to determine how well alternative locations will fit with the existing network. Lanuse is a major factor affecting the pattern of traffic
