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Alireza Naimi

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Papers by Alireza Naimi

Research paper thumbnail of An Innovative Approach to Solve the Network Design Problem Concerning Intelligent Vulnerabilities Transportation Research Board 95th Annual MeetingTransportation Research Board

In today’s congested transportation networks, disturbances like crashes may cause unexpected and ... more In today’s congested transportation networks, disturbances like crashes may cause unexpected and significant delays. All transportation networks are vulnerable to disruptions, to some extent, with temporary or permanent effects. Vulnerability is more important in urban transportation networks, due to heavy use and road segments that are close to each other. Small disturbances on an urban transportation network segment can have a huge impact on its accessibility. Intelligent adversaries may take advantage of these vulnerable parts of the network in order to disrupt the transportation operations, and increase the overall transportation cost for the users. Often, the decision of improving the networks in transportation planning and management tasks are made without adequately taking into account the possible vulnerabilities. By considering the factor of vulnerability in their decision, planners could prevent severe unforeseen disruptions in the future. This study proposes an innovative model for designing robust networks against intelligent attackers. In the model, three decision makers are considered: the network manager/designer, the adversary (intelligent attacker) and the users of the network. Numerical experiments were conducted, and the results proved the potential benefits of the proposed model

Research paper thumbnail of The Robust Urban Transportation Network Design Problem

Research paper thumbnail of Impacts of the 1811-1812 Earthquakes on Existing Transportation Networks in Memphis Area

In this paper we try to simulate the response of a typical bridge to earthquake loading. Bridges ... more In this paper we try to simulate the response of a typical bridge to earthquake loading. Bridges are one of the most important components of transportation systems. Their importance is not just due to monetary or life losses that may occur during earthquake event, but because they are important lifelines and their loss of functionality can cause many losses after the earthquake. In previous earthquakes many bridges experienced failure at their approach and roadway embankments for example we can mention the failure of bridge embankment in Haiti (M7.0), Chile (M8.8) and Tohoku (M9.0) earthquakes. Because of vulnerability of bridge at its embankment the investigation of soil structure interaction at this part is a fundamental problem in study of bridge seismic response. The main concentration of this paper is on investigation of SSI at approach embankment. Two different models are developed and the results are compared.

Research paper thumbnail of Developing a training software system about ITS-road related concepts

Research paper thumbnail of Study on simultaneous using of speed, overtake, time headway controlling system, by AKITS software

Research paper thumbnail of AKITS: An Innovative tool to evaluate ITS solution

Research paper thumbnail of A Geographical Information System Analysis, Using Python: Finding the Most Suitable Areas for Emergency Services, in Terms of Accessibility

Research paper thumbnail of A cost/benefit analysis case study on widening of Lamar corridor in Memphis

Research paper thumbnail of Secondary Crash Identification in Large Scale Highway Networks

Research paper thumbnail of Effect of Primary and Secondary Crashes: Identification, Visualization and Prediction

Research paper thumbnail of Identification of Secondary Crashes in Large-Scale Highway Networks

Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in ... more Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in traffic delay and reduced safety. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes, reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, their identification along with the primary contributing factors is imperative. The objective of this study is to develop a procedure to identify SCs using a static and a dynamic approach in a large-scale multimodal transportation network. The static approach is based on pre-specified temporal and spatial thresholds while the dynamic is based on shockwave principles. The procedure is applied in the State of Tennessee and results show that the dynamic approach can identify secondary crashes with better accuracy and consistency.

Research paper thumbnail of Development of a Secondary Crash Identification Algorithm and occurrence pattern determination in large scale multi-facility transportation network

Transportation Research Part C: Emerging Technologies, 2015

Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in ... more Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in traffic delay and reduced safety. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes in order to reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, their identification along with the primary contributing factors is imperative. The objective of this study is to develop a procedure to identify SCs using a static and a dynamic approach in a large-scale multimodal transportation networks. The static approach is based on pre-specified spatiotemporal thresholds while the dynamic approach is based on shockwave principles. A Secondary Crash Identification Algorithm (SCIA) was developed to identify SC on networks. SCIA was applied on freeways using both the static and the dynamic approach while only static approach was used for arterials due to lack of disaggregated traffic flow data and signal-timing information. SCIA was validated by comparison to observed data with acceptable results from the regression analysis. SCIA was applied in the State of Tennessee and results showed that the dynamic approach can identify SCs with better accuracy and consistency. The methodological framework and processes proposed in this paper can be used by agencies for SC identification on networks with minimal data requirements and acceptable computational time.

Research paper thumbnail of An Innovative Approach to Solve the Network Design Problem Concerning Intelligent Vulnerabilities Transportation Research Board 95th Annual MeetingTransportation Research Board

In today’s congested transportation networks, disturbances like crashes may cause unexpected and ... more In today’s congested transportation networks, disturbances like crashes may cause unexpected and significant delays. All transportation networks are vulnerable to disruptions, to some extent, with temporary or permanent effects. Vulnerability is more important in urban transportation networks, due to heavy use and road segments that are close to each other. Small disturbances on an urban transportation network segment can have a huge impact on its accessibility. Intelligent adversaries may take advantage of these vulnerable parts of the network in order to disrupt the transportation operations, and increase the overall transportation cost for the users. Often, the decision of improving the networks in transportation planning and management tasks are made without adequately taking into account the possible vulnerabilities. By considering the factor of vulnerability in their decision, planners could prevent severe unforeseen disruptions in the future. This study proposes an innovative model for designing robust networks against intelligent attackers. In the model, three decision makers are considered: the network manager/designer, the adversary (intelligent attacker) and the users of the network. Numerical experiments were conducted, and the results proved the potential benefits of the proposed model

Research paper thumbnail of The Robust Urban Transportation Network Design Problem

Research paper thumbnail of Impacts of the 1811-1812 Earthquakes on Existing Transportation Networks in Memphis Area

In this paper we try to simulate the response of a typical bridge to earthquake loading. Bridges ... more In this paper we try to simulate the response of a typical bridge to earthquake loading. Bridges are one of the most important components of transportation systems. Their importance is not just due to monetary or life losses that may occur during earthquake event, but because they are important lifelines and their loss of functionality can cause many losses after the earthquake. In previous earthquakes many bridges experienced failure at their approach and roadway embankments for example we can mention the failure of bridge embankment in Haiti (M7.0), Chile (M8.8) and Tohoku (M9.0) earthquakes. Because of vulnerability of bridge at its embankment the investigation of soil structure interaction at this part is a fundamental problem in study of bridge seismic response. The main concentration of this paper is on investigation of SSI at approach embankment. Two different models are developed and the results are compared.

Research paper thumbnail of Developing a training software system about ITS-road related concepts

Research paper thumbnail of Study on simultaneous using of speed, overtake, time headway controlling system, by AKITS software

Research paper thumbnail of AKITS: An Innovative tool to evaluate ITS solution

Research paper thumbnail of A Geographical Information System Analysis, Using Python: Finding the Most Suitable Areas for Emergency Services, in Terms of Accessibility

Research paper thumbnail of A cost/benefit analysis case study on widening of Lamar corridor in Memphis

Research paper thumbnail of Secondary Crash Identification in Large Scale Highway Networks

Research paper thumbnail of Effect of Primary and Secondary Crashes: Identification, Visualization and Prediction

Research paper thumbnail of Identification of Secondary Crashes in Large-Scale Highway Networks

Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in ... more Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in traffic delay and reduced safety. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes, reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, their identification along with the primary contributing factors is imperative. The objective of this study is to develop a procedure to identify SCs using a static and a dynamic approach in a large-scale multimodal transportation network. The static approach is based on pre-specified temporal and spatial thresholds while the dynamic is based on shockwave principles. The procedure is applied in the State of Tennessee and results show that the dynamic approach can identify secondary crashes with better accuracy and consistency.

Research paper thumbnail of Development of a Secondary Crash Identification Algorithm and occurrence pattern determination in large scale multi-facility transportation network

Transportation Research Part C: Emerging Technologies, 2015

Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in ... more Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in traffic delay and reduced safety. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes in order to reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, their identification along with the primary contributing factors is imperative. The objective of this study is to develop a procedure to identify SCs using a static and a dynamic approach in a large-scale multimodal transportation networks. The static approach is based on pre-specified spatiotemporal thresholds while the dynamic approach is based on shockwave principles. A Secondary Crash Identification Algorithm (SCIA) was developed to identify SC on networks. SCIA was applied on freeways using both the static and the dynamic approach while only static approach was used for arterials due to lack of disaggregated traffic flow data and signal-timing information. SCIA was validated by comparison to observed data with acceptable results from the regression analysis. SCIA was applied in the State of Tennessee and results showed that the dynamic approach can identify SCs with better accuracy and consistency. The methodological framework and processes proposed in this paper can be used by agencies for SC identification on networks with minimal data requirements and acceptable computational time.

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