This document discusses traffic simulation and modelling. It covers different types of traffic models including microscopic, mesoscopic, and macroscopic models. Microscopic models track individual vehicles, macroscopic models aggregate traffic flow data, and mesoscopic models have aspects of both. Simulation models are presented as an alternative to analytical models which require extensive field data collection. The advantages of simulation include being cheaper than field studies and allowing testing of alternative strategies. Current traffic simulation software can model traffic flow at different scales.

1. TRAFFIC SIMULATION AND MODELLING
NAME : DHRUV J. PATEL
SUBJECT : TRANSPORTATION ENGINEERING – 1
ID NO : D18CL124
DIV : 2
BRANCH : CIVIL

2. INTRODUCTION
• Traffic flow phenomenon consists of a wide range of complex
activities,embrancing vehicle arrivals,speed of travel,lane
discipline ,overtaking and crossing logic, gap
acceptance,acceleration and deceleration.
• Different road characteristics will be govern by vehicle
performance, characteristics and behaviour of road user.
• The understanding of traffic flow can be attain by observing
how the vehicles move into the traffic stream by mathematical
models or analytical method.

3. INTRODUCTION
• The analytical approach requires that field data be collected on
a large scale.
i,e. If a proper understanding of a complex haterogeneous
traffic on INDIAN ROAD is to be achieved, Real life obervations
need to be collected.
• Like pavement widths, Roughness, Curvature ,Vertical profile
etc, So it is tedious
• Time consuming and expensive
• At last if still it has been done but the results are uncertain.

5. TRAFFIC MODELS
TRAFFIC FLOW MODELS
I. MICRO
II. MESO
III. MACRO

6. TRAFFIC MODELS
Traffic analytical models are ,where the solution to a set of
differential equations describing the traffic system is obtained
analytically,
• Analytical models can be static and Dynamic
• Numerical methods are used for solutins
But analytical models require large amount of field data such
as, Road Width, Lane Width,Roughness, Complete info. On
geometric design,Vehicle composition,Traffic Volumes, Speed
and Density.
• Extremely Costly and Tedious
• Often uncertainties are involved in the data

7. TRAFFIC MODELS
The simulation models are where the successive changes of the
traffic system over time are reproduced (Approximated)in the
model.
• Simulation models are Dynamic
• Macroscopic, Mesoscopic and Microscopic

8. TRAFFIC MODELS
• Traffic simulation models can be classified as either
microscopic, mesoscopic, or macroscopic.
• Microscopic models are models that continuously or discretely
predict the state of individual vehicles.
• Microscopic measures are individual vehicle speeds and
locations.
• Macroscopic models aggregate the description of traffic flow.
• Macroscopic measures of effectiveness are speed, flow and
density.
• Mesoscopic models are models that have aspects of both macro
and microscopic models.

9. TRAFFIC MODELS
Macroscopic Simulation
o Macroscopic simulation models are based on the deterministic
relationships of the flow, speed, and density of the traffic
stream.
o The simulation in a macroscopic model takes place on a
section-by-section basis rather than by tracking individual
vehicles.
o Macroscopic simulation models were originally developed to
model traffic in distinct transportation subnetworks, such as
freeways, corridors (including freeways and parallel arterials),
surface-street grid networks, and rural highways

10. TRAFFIC MODELS
 Mesoscopic Simulation
o Less mature than either micro- or macro-scale methods
o Tries to combine the advantages of both
 Detail (microscale)
 Scalability to larger networks (macroscale)
o Approaches a discrete microscale simulation when rules are
simple and units are small.
o Approaches a macroscale simulation as the units become larger
and the rules more complex.

11. TRAFFIC MODELS
 Microscopic Traffic Simulation
o Unlike Macroscopic simulation, every vehicle in Microscopic
o There are three behaviors:
 Accelerations
 Braking decelerations
 Lane changes
o In order to achieve accuracy in modeling the traffic, many
factors must be considered. This leads to a simulation model
with high degree of parameters (50 parameters model is
common).

14. DEVELOPMENT OF SIMULATION
• New technique to solve the traffic problems
• It is a working analogy of real life problems into a computer
based model
• It is a technique where part of a real world is represented
dynamically by building a computer model , running the model
through time to solve problems having any given constraints
and inputes.

15. ADVANTAGES OF SIMULATION
• It is cheaper than any other on field methods
• It is a powerful tool for comparing the consequences of
alternative strategies and improvement plan
• Better involvement of competent authority
• In real life situation, It will be difficult to obtain condition in the
field which are needed for building a better analytical
formulation
• These techniques can be employed to check uncertain analytical
solution
• Some of the solution are doughtful in nature, simulation can
overcome with such deficiencies
• Simulation models are transparent

16. MAIN FACTOR OF TRAFFIC SIMULATION
• Advanced research in traffic theory
• Advancement in computer hardware technology
• Advancement in computer software technology
• Development in information
• Increased importance of traffic and transportation in the
society

17. CURRENT SIMULATION SOFTWARE