Introduction of Traffic System
The traffic system is a very important system in every country that ensures
citizens are following the rules effectively as well as it also helps to
control the accidents and death rates on the roads. After passing some time some
ambiguities, as well as some problems, may rise into the current traffic
system. Due to this reason, the risk of failure of the complex traffic system
may also increase. To make the complex
system powerful and successful, it is necessary to validate the complex system.
The current study is completely based on the previous assignment and the
selected project on the complex traffic system is
the traffic flow of a city. In
this document, it is tried to validate a complex system that is selected in the
assignment. The complex system for the city traffic modeled in the previous assignment.
The research study is providing brief information on the complex system in the
form of related studies. The literature study is also providing information on how
other researchers have validated their modeled complex systems. Furthermore, the
brief justification for modeled traffic flow of a city is also provided in the
complex system. The main part of this research work is to validate the modeled complex
traffic system. The reflection part is providing the information related to the
whole study and providing the analysis on the project.
Literature Review of Traffic System
As
described by Toledo & Koutsopoulos (2004), the dynamics of traffic
phenomena’s detailed analysis is supported by traffic simulation models. Therefore,
these models are also important tools for the analysis of the transportation
systems. Furthermore, the simulation models must be able to repeat reality
adequately to evaluate or validate the actual effects of traffic management
systems in the city. The validation model for complex traffic systems is
discussed in the study which is the process of investigating the model
replicates reality. the validation role is defined in the calibration and model
development scope as well as the framework to perform the validation is
discussed. To validate the different types of replication outputs, the
statistical methods hierarchy is investigated against the observed data. Furthermore,
the method for validation is introduced on the basis of statistical tests on
the metamodels formfitting to the simulated data. The applicability of several methods
is illustrated by the case study (Toledo &
Koutsopoulos, 2004).
Balakrishna,
Koutsopoulos, & Ben-Akiva (2005) stated in the research that the
intelligent transportation systems have the ability to make improvements in the
conditions of traffic as well as minimize the delays in traveling through
facilitating better utilization of the accessible and existing capacity. To
achieve their objectives, this type of system is complicated and employs the
algorithms. For the wide range of ITS applications, it has developed many
dynamic traffic assignment systems based on the simulation. Furthermore, more
realistic approaches are targeted by such systems to short term planning for
transportation like work zones and special events. Moreover, it also addresses
the growing real-time applications importance like route guidance, incident
management as well as emergency response (Balakrishna,
Koutsopoulos, & Ben-Akiva, 2005).
As
stated by Schaefer, Vokřínek, Pinotti, & Tango (2016) that an integrated
multi-agent simulation unified platform for providing support development and autonomic
traffic system validation. The simulation is allowing to validate the
coordination strategies of the car to car in different scenarios into the
penetration levels of variable technology such as mixing of different
strategies. Furthermore, it also allows the acceptance of the users of the
traffic system as part of the traffic system or as the external observer of the
traffic system. Furthermore, the realistic driving simulation features are
combined by the platform while the vehicles were controlled by AI and
simulation with a flexible detail level. The platform’s principal idea is to
allow the development and the complex autonomic study distributed car to car
system for the coordination of vehicles. The development environment is
provided by the platform and the toolchain which is essential for the validation
of the complex traffic systems. So, the autonomic complex systems are
completely based on the coordination approach among the agents (Sutandi
& Dia, 2005).
The
traffic of road is demonstrated as a multi-specialist arrangement of agreeable
operators. The cooperation between the operators carries autonomic properties
into the developed framework (for example the traffic adjusts to a blockage of
a path and vehicles converge into a subsequent path). The framework likewise
shows autonomic properties from a solitary client viewpoint. The driver moves
toward the framework in a type of a driver help framework. The researchers can indicate
it as an autonomic driver help framework. With the assistance system though the
human-machine interface, it is only being interacted by the driver. The
complexity of multi-agent interactions is being hidden by the autonomic driver's
assistance from the user. In the last of this study, the specific agent of the car
will be responsible to interact with other agents in the system without any
intervention of the user (Schaefer, Vokřínek,
Pinotti, & Tango, 2016).
Image below shows the Multi-agent Traffic stimulation.
As
stated by Xiang, Kennedy, Madey, & Cabaniss (2005), the most formalized
model validation and verification approaches come from the system and
industrial engineering for the simulations of the discrete event systems.
Furthermore, such kind of techniques is highly recommended and used in the computational
sciences. But the technique of agent-based modeling is completely different
from the approaches of discrete event modeling on a larger basis which is
mostly used in different several areas of industrial and system engineering. The
researchers have also further said that an attractive and efficient way for
modeling the complex systems on a larger scale, have recently been become by
the agent-based modeling techniques. For agent-based model validation, there
are also some formalized approaches existing which have the ability to validate
the traffic complex systems. Several types of existing validation and
verification techniques are designed, developed, adopted, and applied by
researchers in this research study to an agent-based scientific model. Therefore,
they have also investigated the importance and sufficiency of such kind of
approaches to validate the models of agent-based (Xiang, Kennedy, Madey,
& Cabaniss, 2005).
Pütz,
Zlock, Bock, & Eckstein (2017) have stated in their research that the
signing of highly automated vehicles is an important problem for the industry
of autonomous vehicles. the high test efforts are caused by the assistance
systems for automated vehicles. The validation framework is developed by the
project PEGASUS for the sign of the process of such vehicles. The relevant
traffic scenarios are being contained by one element of this framework. Different
types of database entities are combined by the database. Moreover, such kind of
database entities is described by the researchers in this study and the
processing chain steps including the resulting benefits for the validation. Furthermore,
the collection approach to sign off on the common database, as well as the
criteria for the common evaluation, are also discussed in this study (Pütz,
Zlock, Bock, & Eckstein, 2017).
Complex System of Traffic
The complex
system for city traffic flow which is modeled in the previous assignment is
completely based on logic. In the design of the road map model of the complex
system was generated randomly in every setup but the size of the roads and map
based on the input size. Every intersection on the roads has signal lights because
the different roads are intersecting each road. That’s why the signal lights
are essential in every intersection to control the movement of vehicles and
give the instructions to cars to run or stop. The design is also selected
because the traffic simulation weather sensitive. The traffic signaling and the
workability will have the standard behavior but the rainy weather will make the
road slippery. Because of this situation, it is possible to increase the number
of accidents. But the design for weather will be effective because the network
of roads and signals and the barriers fixed on the roads can reduce the rate of
accidents in different weathers. On the other side, the main challenge in the
design was the pedestrians but it was also handled by setting some rules and
regulations on crossing roads and they will not be hit by cars on roads.
Image shows the complex and increasing capacity of traffic system that
lies on different factors.
Validation Metric of Traffic System
Types of roads
|
The output of model performance
|
Data used in calibration
|
Urban
|
Traffic counts
|
Detector data for 30 min during the a.m. peak
|
Freeway
|
Traffic Volume
|
Data 5 loop detector stations for 13 min section of the freeway for 30
min during both P.M and A.M peak
|
Freeway
|
Volume
|
5 min data from 21 detector stations for 10 min freeway section during
the peak of pm for 2 days
|
Urban intersection
|
Time of travel
|
Data of detector for 15 days for peaks of p.m and a.m on the large
network
|
Freeway, arterial
|
Density and Speed,
|
The data form the 5 detector stations on 3 freeways at the time of a.m
peak for 1 week
|
Urban freeway network
|
Flow, occupancy
|
5 min detector count during the peak of p.m for 1 week
|
Freeway
|
The flow of the traffic
|
Loop detector data
|
Freeway
|
Distribution of the travel time
|
The trajectory of NGSIM data for the streets for 30 mins
|
Urban intersection
|
Distribution of the traffic flow and time
|
5 min detector count during the peak of a.m.
|
Pedestrians
|
Time of traveling on the urban roots
|
1-hour detector count during the peak of a.m and p.m
|
Reflection of Traffic System
In this
section, the brief information on this research study by reflection on the models,
literature study as well as the findings. First of all, the study is providing
brief information that the design of the road map is completely logical which
will be changed in every setup. there is a huge network of roads which are
intersecting each other and they all have the traffic lights that will control
the traffic. The detectors are counting the movements and activities of
vehicles and pedestrians on the roads. The validation metric is providing information
that the detectors are working normally and the whole traffic system too. The
satisfying fact of this study is that the model is preventing deadlocks and
accidents and any kind of blockage.
Conclusion of Traffic System
It is
concluded that the traffic system is a very important system in every country
that ensures citizens are following the rules effectively as well as it also
helps to control the accidents and death rates on the roads. The complex system
for the city traffic modeled in the previous assignment. The dynamics of traffic phenomena’s detailed
analysis is supported by traffic simulation models. More realistic approaches
are targeted by such systems to short term planning for transportation like
work zones and special events. Furthermore, the realistic driving simulation
features are combined by the platform while the vehicles were controlled by AI
and simulation with a flexible detail level. The traffic of road is demonstrated
as a multi-specialist arrangement of agreeable operators. The complexity of
multi-agent interactions is being hidden by the autonomic driver's assistance
from the user. For agent-based model validation, there are also some formalized
approaches existing which have the ability to validate the traffic complex
systems. The validation framework is developed by the project PEGASUS for the
sign of the process of such vehicles. The relevant traffic scenarios are being
contained by one element of this framework. In the design of the road map model
of the complex system was generated randomly in every setup but the size of the
roads and map based on the input size. The traffic signaling and the
workability will have the standard behavior but the rainy weather will make the
road slippery. The study is providing brief information that the design of the
road map is completely logical which will be changed in every setup. The
validation metric is providing information that the detectors are working
normally and the whole traffic system too.
References
of Traffic System
Balakrishna,
R., Koutsopoulos, H. N., & Ben-Akiva, M. (2005). Calibration and Validation
of Dynamic Traffic Assignment Systems. In Transportation and Traffic Theory.
Flow, Dynamics and Human Interaction. 16th International Symposium on
Transportation and Traffic TheoryUniversity of Maryland, College Park.
Hоуеr, R., &
Fellendorf, M. (1997). Parametrization of Microscopic Traffic Flow Models
Through Image Processing. IFAC Proceedings Volumes, 889-894.
Pütz, A., Zlock, A.,
Bock, J., & Eckstein, L. (2017). System validation of highly automated
vehicles with a database of relevant traffic scenarios. 12th ITS European
Congress, Strasbourg, 19-22.
Schaefer, M.,
Vokřínek, J., Pinotti, D., & Tango, F. (2016). Multi-Agent Traffic
Simulation for Development and Validation of Autonomic Car-to-Car Systems. Autonomic
Road Transport Support Systems, 165-180.
Sutandi, A. C., &
Dia, H. (2005). Performance Evaluation of An Advanced Traffic Control System In
A Developing Country. Proceedings of the Eastern Asia Society for
Transportation Studies, 1572 - 1584.
Toledo, T., &
Koutsopoulos, H. N. (2004). Statistical Validation of Traffic Simulation
Models. Transportation Research Record: Journal of Transportation reserach
Board.
Xiang, X., Kennedy,
R., Madey, G., & Cabaniss, S. (2005). Verification and validation of
agent-based scientific simulation models. In Agent-directed simulation
conference, 55.