AADT (Annual Average Daily Traffic)
It is 1/ 365th of the total traffic flow.

Access The pedestrian/ Vehicle linkages from the site to/ from existing or planned approaches (urban streets, limited access highway, public transportation system, and other system such as water ways, airlines etc.

Arterial Street
It is a street primary meant for through traffic on a continuous route

Basic Capacity
The maximum number of passenger cars that can pass at a given point, in a lane or on a road during one hour

Carriage way
It is the width of the roadway excluding the shoulders. It is paved width of the road surface. Circulation
System of movement/ passage of people, goods from place to place, streets, walkways, parking area etc.

Collector Street
A collector street is one intended for collecting and distributing traffic to and from street and for providing access to sub-arterial street.

Density on Concentration
It is the number of vehicles occupying a given length of lane or roadway, averaged over time.

District Road
District roads are the roads transferring each district, serving area of production and markets and connecting to these with each other or national or state highways.

Diverted Traffic
Traffic, which has changed from its previous route of travel to another route, without change in origin or destination

Dwell Time
The time for which a transit vehicle is stopped for the purpose of serving passengers (for example, stoppage of a bus for boarding and alighting of passengers.

Express Way
These are divided arterial highway for motor traffic, with full or partial control of access and provided generally with grade separation at intersections. It connects major activity areas and its main function is to provide for movement of heavy volumes of motor traffic at high speed.

Factor of Safety
A measure of the balance between shear stress and shear strength in a slope; a state of limiting equilibrium exits when shearing forces equal resisting forces in a slope and F=1

Flow
It is the number of vehicles passing a specified point during a stated period of time, which is usually expressed in vehicles per hour.

Cul-De-Sac
It is a street leading to a closed end provided with facility of turning of vehicles.

Cycle time
Any complete sequence of signal indication and time associated with it is called cycle time.

Green Time
The length of the green phase plus its change intervals in seconds (in a traffic signal)

Headway
It is the time between successive vehicles as they pass a point on the road.

Hierarchy of Road
Roads are generally classified into two major categories- Urban and Rural

1. Urban Roads - (a) Expressways (b) Arterial Roads (c) Sub-arterial Roads (d) Collector Roads (e) Local Roads
2. Rural Roads - (a) National Highways (b) State Highways (c) Other District Roads (e) Village Roads.

Inter-green time (Clearance interval)
The time period between the end of a green indication of another phase on the traffic signal.

Journey speed
It is the effective speed of a vehicle between two points, i.e. total distance / total journey time (including delays).

Level of services
It is a qualitative measure describing operational conditions within a traffic stream and their perception by drivers or passengers. Six levels of service are recognized commonly designated from A to F where A represents the best operating condition (i.e. free flow) and F is the worst (i.e. forced flow).

Local street
A local street is one primarily intended for access to residence, business or other abutting property.

National Highway
National Highways are the important or main highways running through the length and breadth of the country, connecting ports, highways and capitals of states and including roads of strategic and military value.

Origin and destination survey
A survey to determine the origin and destination of journeys.

Parking accumulation
The total number of vehicles parked in an area at a specified time.

Parking duration
The length of time spent in a parking space.

Parking Index
Percentage of the theoretically available number of parking bays actually occupied by parked vehicles.

Parking turnover
Rate of the usage of available parking space.

Parking volume
The number of vehicles parked in a particular area over a given period of time. It is usually measured in vehicles per day.

Passenger Car Unit (PCU)
To express capacity of roads, the term passenger car unit is used. The basic consideration behind this practice is that different types of vehicles offer different degrees of interference to other traffic and it is necessary to bring all types to a common unit. The common unit adopted is called 'passenger car unit'.

Peak hour factor
It is defined as the traffic volume during peak hour expressed as a percentage of the ADT.

Practical Capacity
The maximum number of vehicles that can pass during one hour without the traffic density being so great as to cause unreasonable delay, hazard under prevailing roadway and traffic condition.

Public transportation system
These are modes of passenger transport that are open that are open for public use.

Rate of flow
It represents the number of vehicles passing a point during a time interval less than one hour but expressed as an equivalent hourly rate.

Right of way
It is the width of the land secured and preserved for the public road purposes. It should be adequate to accommodate all the elements that make up the cross-section of the highway and may reasonably provide for future development.

Road/ Street
Any highway, street, lane, pathway, alley, stairway, passageway, carriage-way, footway, square, place or bridge, a thoroughfare or not, over which the public have a right of passage or access or have passed uninterruptedly for a specified period, whether existing or proposed in any scheme, and includes and all bunds, channel, ditches, storm water drains, culverts, sidewalks, traffic islands, roadside trees and hedges, retaining walls, fences, barriers and railings within the street lines.

Running speed
It is the average speed maintained by a vehicle over a given course while the vehicle is in motion i.e running time.

Screen line
An imaginary line drawn across part of a traffic study area, across which the total number of movements of any particular kind are determined, in order to check the estimated traffic flows across same line.

Service lanes
Service lanes are roads provided adjacent to major roads on both sides. They will be connected with the major road once in a kilometer or so. This is to control the access to major roads so that thorough traffic is not disturbed much.

Space Mean speed
It is the average of the speed measurements at an instant of time over a space.

Spacing
The distance between successive vehicles in a traffic stream measured form front bumper .

Speed
Speed is the rate of movement of traffic or a specified component of traffic and is expressed in metric unit or kilometer per hour.

State Highway
They are the other main trunk or arterial roads of a state, connecting up with national headquarters and important cities within the state.

Street Lighting
Illumination to improve vision at night for security and for the extension of activities

Sub Arterial street
Provide access to adjoining areas and are used for parking, loading, unloading , are usually restricted and regulated.

Time Mean Speed
It is the average of the speed measurements at one point in space over a period of time.

Traffic Volume
It is the actual number of vehicles observed or predicted to be passing a point during a given time interval.

Trip
A one -way movement between a point of origin and a point of destination.