• Types of volume measurements

1. Average Annual Daily Traffic(AADT): The average 24-hour traffic volume at a given location over a full 365-day year, i.e. the total number of vehicles passing the site in a year divided by 365.

• 2. Average Annual Weekday traffic (AAWT): The average 24-hour traffic volume occurring on weekdays over a full year. It is computed by dividing the total weekday traffic volume for the year by 260.

• 3. Average Daily traffic (ADT): An average 24-hour traffic volume at a given location for some period of time less than a year. It may be measured for six months, a season, a month, a week, or as little as two days. An ADT is a valid number only for the period over which it was measured.

• 4. Average Weekday traffic (AWT): An average 24-hour traffic volume occurring on weekdays for some period of time less than one year, such as for a month or a season.

Speed Studies

Types of Speedo Spot speedo Time mean speedo Space mean speed

Application of speed datao Analysis of speed pattern along the roado Planning and design of traffic facilities o Fixing design speed of road lengtho Accident studies o Traffic capacity

Data Collectiono Measure of Speed using Enoscope o Radar Guno Photographo Video camera

Speed and Delay Study

• Efficiency of the road can be judged from this study.

• Gives, running speed, overall speed, fluctuations in speed and delay between the stations.

• Amount, location, duration, and causes of the delay in the traffic stream.

Methods of carrying Speed and Delay study• Floating car method or riding check method• License plate or vehicle number method• Interview technique• Photographic technique

• Origin and Destination Studies • Determines nos. of trip, their origin and destination in each zone under

study. • Nos. of passenger in each vehicle, purpose of trip, intermediate stop made

and reason etc. • Gives direction of travel, selection of route, and length of the trip.

The various application of origin and destination studyo .To judge adequacy of the existing route and to use in planning of new

network of roadso In planning transportation system of a city including mass

transportation ,routes and their schedule. o Locate expressway o Locate terminals and to plan terminal facilities o Locate intermediate stops of public transport

Data Collection• Road side interview• License plate method• Return post card method• Tag on car method• Home interview method• Work spot interview

• Traffic flow characteristics and studies • Traffic capacity studies

• Parking studies

• Parking studies includes o Availability of parking spaceo Extent of its usageo Parking demand

Parking demand:

1. Counting vehicle at high peak hour at cordon of a selected area

2. Counting parked vehicles at regular interval of time

3. Interviewing the driver, owner of vehicle

Parking characteristics • On-street parking • Off street parking

Parking space inventory

Accident studies

• Objectives of accident studies • to study the causes of accident • To evaluate the existing facilities • To support propose design• To make computation of financial loss

Various causes of accidents are o Drivers o Padestrianso Passengers o Vehicle defecto Road conditiono Road designo Weather (fog, mist, snow, dust rain)o Animals o Other causes

PCU

Factors affecting PCU values o Vehicle characteristics o Traffic stream characteristicso Roadway characteristics o Regulations and controls of traffic o Transverse and longitudinal gaps

• Density• Density is defined as the number of vehicles occupying a given length of

highway or lane and is generally expressed as vehicles per km.

• One can photograph a length of road x, count the number of vehicles, nx, in one lane of the road at that point of time and derive the density k as,

Fundamental relations of traffic flow

• The relationship between the fundamental variables of traffic flow, namely speed (v), volume (q), and density (k) is called the fundamental relations of traffic flow.

Traffic intersections

• Unsignalized Intersection• Stop and yeild control gaps • Channelization• Length of Auxiliary lanes• Rotaries

• Signalized Intersection