• It is also provided on horizontal curve so as to provide a better night visibility of the curves under the head light of the vehicle.
Road margins Parking lane: • These are provided on urban roads to allow kerb parking • As far as possible only parallel parking should be allowed as it is safer for moving vehicle. • It should have sufficient width say 3m Lay bay: • These are provided near the public conveniences with guide map to enable driver to stop clear off the carriageway. • It has 3m width,30m length with 15m end tapers on both sides. Bus bays: • These may be provided by recessing the kerb to avoid conflict with moving traffic. • It is located atleast 75m away from the intersection.
Frontage road: • These are provided to give access to properties along an important highway with control access to express way or free way • It may run parallel to the highway and are isolated by separator. Driveway: • It connect the highway with commercial establishment like fuel stations, service stations etc… • It should be located away from the intersection. Cycle track: • It provided in urban areas when the volume of cycle traffic on the road is very high. • A minimum width of 2m is provided for cycle track. Footpath: • These are provided in urban areas when the vehicular as well as pedestrian traffic are heavy. • To protect the pedestrian and decrease accident. • Minimum width of 1.5m is provided.
c/s of highway in hilly area
c/s of road in built-up area
C/S of Flexible pavement C/S of Rigid pavement
c/s of road in cutting
Bibliography • Khanna , S. K., & Justo, C. E. G. “ Highway engineering”. Nem Chand & Bros. • IRC Codes.
Lecture -3 Sight Distance & Horizontal Alignment Civil Engineering Department College of Engineering and Technology(CET) Bhubaneswar TRANSPORTATION ENGINEERING-I PCCI4302
SIGHT DISTNCE • Sight distance available from a point is the actual distance along the road surface, which a driver from a specified height above the carriageway has visibility of stationary or moving objects. OR • It is the length of road visible ahead to the driver at any instance.
Types of sight distance • Stopping or absolute minimum sight distance(SSD) • Safe overtaking or passing sight distance (OSD) • Safe sight distance for entering into uncontrolled intersection. • Intermediate sight distance • Head light sight distance
Stopping sight distance: • The minimum sight distance available on a highway at any spot should be of sufficient length to stop a vehicle traveling at design speed, safely without collision with any other obstruction. Over taking sight distance: • The minimum distance open to the vision of the driver of a vehicle intending to overtake slow vehicle ahead with safety against the traffic of opposite direction is known as the minimum overtaking sight distance (OSD) or the safe passing sight distance.
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- Spring '14
- Science, Road, sight distance, IRC, road network, Central Road Fund