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CARRIAGE WAYTransportation And Traffic For Urban DesignSubmitted by:Aswathy RajagopalM.Ach 1st sem(2014-2015)What is a carriageway?Types of carriagewayWho are the usersStandards in designCarriage way width standardsMaterial and treatmentCONTENTSWHAT IS A CARRIAGEWAY?The traveled way which is used for movement of vehicles, it takes the vehicular loading and predominant vehicle loads is shared by this component which is called carriageway. -IIT KHARAGPURIt is the width of the road which is used by the traffic for moving on it. It is generally central portion of the total land width and is paved and surfaced with the bituminous concrete for service to the road users. -TRANSPORTATIONENGINEERING

CARRIAGE WAY+SHOULDER = ROADWAY

CARRIAGEWAYSHOULDERSHOULDER

CARRIAGEWAYCARRIAGEWAYTYPES OF CARRIAGEWAYThere are two types of carriageway:1.Single carriageway:Asingle carriagewayroad has one carriageway with 1, 2 or more lanes together with any associatedfootwaysandroad verges.

2.Dual carriageway:Adual carriagewayroad has two roadways separated by acentral reservation.

Alocal-expresslane system has more than two roadways, typically two sets of 'local lanes' or 'collector lanes' and also two sets of 'express lanes'.

WHO ARE THE USERS?The primary users of the carriageway is the vehicles and the road width is designed to accommodate the design traffic volume.

STANDARDS IN DESIGNThe design of the width of carriageway is decided on the traffic volume present and based on the future estimations.The road should be designed to accommodate the traffic volumes computed for the end of design life, for eg. Design period of 15-20 years should be adopted for arterial roads and 10-15years for local and collector streets.The lane widths of a carriageway affect the safety and driving behavior of drivers. Wide lanes encourage higher speeds.Horizontal clearance for urban arterials, sub arterials , collectors, and local streets where curbs are utilized, space for clear zones is generally restricted. A minimum offset distance of 500 mm [18 in] should be provided beyond the face of the curb, with wider offsets provided where practical.

CARRIAGEWAY WIDTH STANDARDSRecommended carriageway widths are as below:DescriptionWidth(m)Single lane without curbs3.502-lane without curbs7.002-lane with curbs7.503-lane with or without curbs10.5/11.04-lane with or without curbs14.06-lane with or without curbs21.03.50M CARRIAGEWAY

7M CARRIAGEWAY

7.50M CARRIAGEWAY10.5M -11.0M CARRIAGEWAY

14M CARRIAGEWAY

21M CARRIAGEWAY

Source: IRC-86

Design speed and carriageway width recommended for different road categories Source: MoUD Design of Urban Roads-Code of Practice

MATERIAL AND TREATMENT

Earth workWet mix macadam(wmm)Bituminous macadam(bm)Bituminous concrete(bc)Granular sub base(gsb)Tack coatEarth Work:Soil fillingSpreading & leveling

Compaction of sub gradeI Layer :200mmII ,III Layer :150mm

Granular sub base:MaterialLayersDepthCompaction

Wet mix macadam:MaterialLayersDepthCompaction

Sub Base layerBituminous macadam:Bituminous macadam consists of aggregate and appropriate binder, mixed in a hot mix plant and laid with a mechanized paver.It is an open graded mixture suitable for base course and is laid in a single course or in multiple layers on a previously prepared base.It is a road base material consistingof crushed rock/slag usually premixed with controlled amount of water sufficient for adequate compaction.

Finishing of surface:

Bituminous concreteLayers of carriage way are:Earth workGranular sub base(GSB)Wet mix macadam(WMM)Bituminous macadam(BM)Bituminous concrete(BC)Tack coat