Nima Alizadeh, Highway Design Engineer

How do you increase the efficiency of interchanges in a crowded and traffic-loaded metropolis?




Simulation of an interchange in the Buca district of Izmir, Turkey

Metropolitan cities around the world are facing major struggles with their transportation system. Living in one of these cities – namely Istanbul – I experience these problems on a daily basis. As a highway design engineer and traffic planner, I want to take a step forward in resolving these issues and create better and safer connection networks.
The challenge: Creating the best possible interchange
I am working for a company that has been assigned to design a new highway interchange in Buca, a district of Izmir. Traffic volume in this area is high and the project zone is surrounded by public facilities, such as a cemetery and a hospital. As the design engineer responsible for the project I decided to design an interchange that not only guarantees easy and comfortable access to the facilities, but also increases the capacity and gets rid of conflict areas.

“I designed an interchange in Izmir, Turkey, that guarantees easy access to the nearby hospital and cemetery, reduces conflicts and increases capacity.”


Which design is the best?
We created various design alternatives using the commercial engineering software Civil 3D. Doing this, we had to keep in mind the constraints and criteria we had been given concerning for example land-use and environmental issues. We also had to consider the AASHTO road design criteria. We then compared and evaluated the alternatives and opted for a two-level interchange with maximum capacity that would also guarantee easy access to the nearby public facilities.
Microsimulation as a helpful communications tool
For research purposes and to evaluate the performance and level of service of the interchange, Assistant Professor Yavuz Delice from Yalova University and I additionally created a PTV Vissim simulation. Not only did it help me to design the intersections. Thanks to Vissim’s powerful graphical demonstration, we were also able to more clearly present the output of our engineering work to our clients.
More about Nima
Nima was born on Tabriz, Iran, and has been living and studying there for 27 years. After his bachelor’s degree in civil engineering, he decided to pursue his master studies in transportation engineering at Istanbul Tech University. He has worked for two years on various arrays of traffic simulation projects in Kopal Transportation and Construction Engineering Limited Corp. Currently, he is writing his master thesis and working in parallel as a highway design engineer for the technical consulting corporation BOTEK. To practice his traffic simulation skills and out of curiosity, he sometimes simulates complex and interesting interchanges. He also loves reading books, watch movies and spending time with friends and family. His secret passion? Cooking!
Get to know the PTV Expert:
Jochen Lohmiller, Manager PTV Vissim Product Management at PTV Group
Traffic engineers around the world are struggling with the same question: How do you determine the best possible design for a street, intersection or interchange to guarantee a certain level of service for traffic flow? A microsimulation tool such as PTV Vissim can be very helpful in this decision-making process. It allows you to mimic real road traffic to the finest detail, to assess and evaluate planning alternatives and to avoid costly mistakes. If you would like to learn more, why don’t you join our free User Forum on LinkedIn to connect with microsimulation experts, researchers and practitioners from all over the world.

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