Fundamentals of Traffic Flow Theory

Traffic Engineering (CE 305) Lecture 7 - Fundamentals of Traffic Flow Theory Part 1

 

Traffic Stream is Influenced by

Individual vegicles

Individual draivers

Driver Inetactions

Roadway geometry

Traffic control devices

 

* Not possible to decrive all aspects of traffic flow therothcally

* need quantitive techniques to assess operational measures og highway performance

 

Two types of flow/facility : Uninterrupted/ Interupted

 

Levels of modeling and It's Characteristics

Macrosopic : flow is not individual vehicles

- Volume or flow rate

- Speed

- Density

Microscopic : flow is individual vehicles(lots of details)

- Speed of individual vehicles

- Headway

- Spacing

Mesoscopic : in between the two.

 

 

1. Volume or Flow rate(12:30)

 

q=n/t

- t : second to count

- n : number of vehicle passing some designated point

- q : traffic flow in vehicle per unit time.

 

Daily Volumes

- Average Annual Daily Traffic(AADT)

- Average Annual Weekday Traffic(AAWT) 

 

- Average Daily Traffic(ADT) : average for 1months

- Average Weekday Traffic(AWT) :