functions of roads

7/30/2019 Functions of Roads

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FUNCTIONS OF ROADS

The Functional Classes:

• arterial

• collector

• local

Functional System Services Provided

Arterial Provides the highest level

of service at the greatest

speed for the longest

uninterrupted distance,

with some degree of

access control.

Collector Provides a less highly

developed level of service

at a lower speed for shorter

distances by collecting

traffic from local roads and

connecting them with

arterials.

Local Consists of all roads not

defined as arterials or

collectors; primarily

provides access to land

with little or no through

movement.

Urban Arterial

collector

local



IN RURAL AREAS, roads are divided into five categories, namely

• EXPRESSWAY,

•

HIGHWAY,• PRIMARY ROAD,

• SECONDARY ROAD and

• MINOR ROAD

IN URBAN AREAS, roads are divided into four categories, namely,

• EXPRESSWAY,

• ARTERIAL,

• COLLECTOR AND

• LOCAL STREET.

FUNCTIONS OF ROADS

MINOR ROADS

They form the basic road network within a Land Scheme or other inhabited

area in a rural area. They also include roads with special functions such as holiday resort roads,

security roads or access roads to microwave stations.

They serve mainly local traffic with short trip lengths and are usually with

partial or no access control.



HIGHWAYS

They constitute the interstate national network and complement the expressway

network.

They usually link up directly or indirectly the Federal Capitals, State capitals andpoints of entry/exit to the country.

They serve long to intermediate trip lengths.

Speed service is not so important as in an Expressway but relatively high to medium

speed is necessary.

Smooth traffic is provided with partial access control.

PRIMARY ROAD They constitute the major roads forming the basic network of the road

transportation system within a state.

They serve intermediate trip lengths and medium travelling speeds.

Smooth traffic is provided with partial access control.

They usually 1ink up the State Capitals and District Capitals or other

Major Towns.

SECONDARY ROADS

They constitute the major roads forming the basic network of the road

transportation system within District Regional Development Areas.

They serve lengths with partial access control.

They usually link up the major towns within the District or Regional

Development Areas.

FUNCTIONS OF ROADS



EXPRESSWAY

An Expressway is a divided highway for through traffic with full control of access and

always with grade separations at all intersections.

In rural areas, they apply to the interstate highways for through traffic and make the

basic framework of National road transportation for fast travelling.

They serve long trips and provide higher speed of travelling and comfort.

To maintain this, they are fully access-controlled and are designed to the highest

standards.

In urban areas, they form the basic framework of road transportation system in

urbanised area for through traffic.

They also serve relatively long trips and smooth traffic flow and with full accesscontrol and complement the Rural Expressway.

FUNCTIONS OF ROADS



The arterial roads

provide the highest level of mobility and the highest speeds

over the longest uninterrupted distance. Interstatesnationwide usually have posted speeds between 55 and

75 mi/h.

ARTERIAL ROADS

FUNCTIONS OF ROADS

Collectors

are major and minor roads that connect

local roads and streets with arterials. Collectors provideless mobility than arterials at lower speeds and for shorter

distances. They balance mobility with land access.

The posted speed limit on collectors is usually

between 35 and 55 mi/h.

COLLECTORS

Local roads provide limited mobility and arethe primary access to residential areas,

businesses, farms, and other local areas.

Local roads, with posted speed limits usually

between 20 and 45 mi/h,

are the majority of roads in the U.S.

LOCAL

LOCAL



Relationship of functionally classified

highway systems in serving traffic mobility

and land access.

FUNCTIONS OF ROADS

Arterials higher mobility

low degree ofaccess

Collectors balance between

mobility andaccess

Locals lower mobility

high degree ofaccess



COLLECTOR ROAD

The total width of a rural

collector can vary from

7.2 m to 12 m, dependingon traffic volume.



Functional System Percent of

Total Mileage Percent of

Total Travel Interstate 1.2 22.8 Other Freeway/Expressway .2 6.2 Other PrincipalArterial 3.8 24.3 Minor Arterial 5.7 18.4 Major Collector 11.1 7.8 Minor Collector 7.2 2.1 Collections 2.2 5.3 Local 68.6 13.1

Total 100 100

Functional System (Rural and Urban)

Mileage and Travel

FUNCTIONS OF ROADS



FUNCTIONS OF ROADS

functions of roads

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