2. What is Simulation ?
It is the imitation of real
world or creating a
working analogy real life
using computer-based
model.
Building real world in
computer programme for
finding solutions to
problems of given inputs.
3. Advantages of Simulation Techniques
Cheaper than field experimentation and analytical
modelling ( time, resources and cost ).
Comparing no of alternative strategies and
improvement plans.
An idea on traffic characteristics and the way traffic
interaction takes place during the collection of data and
modelling.
Real life situations can be easily build in computer
programme.
It can be employed to check uncertain analytical
solutions.
4. It also provides opportunity for
controlled experimentation and by
changing the variables we can
observe changes.
Simulation can overcome
deficiencies on assumptions in
conventional methods.
It’s a “ Transparent”, anyone can
see how the work carried out and
what was happening in model.
5. Steps in Simulation
1. Definition of the problem.
2. Field studies to determine inputs needed for modelling.
3. Development of Logic.
4. Development of Computer Simulation Programme.
5. Calibration of Model.
6. Simulation runs covering actual conditions.
7. Validation of the model.
6. 1.Definition of the problem
The initial step involves defining the
problems ( Accidents, fuel consumption ,
speed flow relation )of the study and
determine what needs to be solved. The
problem is further defined through objective
observations of the process to be studied.
7. 2.Field studies to determine inputs
needed for modelling
As this modelling is based on real life happenings ,this
helps in study of the real life behaviour and drawing
conclusions ( inputs ).
Ex:- speeds followed by the drivers can cover the a
complete range depends on characteristics of vehicle,
the road, traffic stream and driver himself
By using simulation model these parameters can be
known to drivers.
8. 3.Development of Logic.
Creating logics such as , In
“T-junctions” traffic of one
road influence the traffic in
other roads. Safe manover
of vehicles in turnings and
avoid risks a logical
operation has to be
developed.
9. 4.Development of Computer Simulation Programme.
Modeller is now in a position to
write simulation programme
which will incorporate the inputs
and logic has determined.
3 –languages normally used
# Fortran
#Algol
#Simula
10. 5. Calibration of Model.
Likely missing of certain essential data have
been erroneously determined.
Initial run of model can be detect some errors.
Its helps in eliminate any inaccuracies
6. Simulation runs.
Once model was calibrated it was ready for
actual use.
It involves all possible extreme conditions of real
life.
11. 7. Validation of the model.
Comparison of Simulation run observations
with real life observations under similar
conditions.
Any inaccuracy in simulations have to be again
investigate the causes of divergence and
recalibrate the model, until satisfactory result
achieved.
12. Applications of Simulation Techniques
Simulation can be applied to both transportation planning and to
transportation design and operations.
Evaluate the impacts of regional urban development patterns on
the performance of the transportation infrastructure.
Lane types, signal timing and other traffic related questions are
investigated to improve local system effectiveness and efficiency.
Operations and design focus on a smaller scale, such as a
highway corridor
Ground transportation for both passenger and goods movement
is perhaps the area where simulation is most widely used.
Simulation can be carried out at a corridor level, or at a more
complex roadway grid network level to analyze planning, design
and operations such as delay, pollution, and congestion.
13. In traditional road traffic models, aggregate
representation of traffic is typically used where all
vehicles of a particular group obey the same rules of
behavior; in micro-simulation, driver behavior and
network performance are included so that complete
traffic problems
