Kaisar, Evangelos I.

Over the last thirty years, intermodal freight transportation has been a constantly expanding sector. The vast increase of freight volumes contributes to the increase of various issues in the freight corridors as well as the urban environment. The deterioration of congestion in the urban environment and the increase on freight movements on the highways have resulted in the increase of emissions. For this reason, new policies and regulations are put forth to address the environmental effects of freight transportation. This study deals with the intermodal freight network design problem from the shipping company's perspective, aiming to simultaneously minimize emission levels and cost of freight transportation. We propose a mathematical model for optimizing the design of an intermodal freight network and the location of intermodal hubs between the origins and the destinations, under delivery time constraints. The goal is to identify the mode choice patterns considering transport cost and emissions, and the effects of new emission regulations on network costs. We consider a network with marine terminals as the origins, inland intermodal terminals as the hubs, and fulfillment centers as the destinations. Numerical experiments highlight that the proposed model can provide useful insights to the shipper.

Freight transportation is a significant component of the nation’s economy. However, the augmented volume of the freight movements contributed to continuously increasing congestion on the urban road networks, that affects the timeliness and reliability of freight transportation. In addition, congestion has a negative impact on the transit operations as well. Various studies conducted on multi-modal corridors recognized the importance of the simultaneous performance of freight and transit operations. Thus, Intelligent Transportation System (ITS) components, such as Freight Signal Priority (FSP) and Transit Signal Priority (TSP), present traffic operations strategies "shaped" to give priority, reduce delay and travel time, and overall improve the performance of freight and transit movements, respectively. The primary objective of the thesis refers to evaluate possible improvements in freight mobility, while sustaining good transit services and minimizing congestion on the multi-modal corridor, through simultaneous implementation of the FSP and the TSP. The effectiveness of the newly established criteria was evaluated through real-world case study on a micro-simulation platform. The results showed significant improvements on all the vehicle movements.

Logistics play a vital role in the prosperity of today’s cities, but current urban
logistics delivery practices have proven problematic and to be causing various negative
effects in cities. This study proposes an alternative method for delivering cargo with the
leasing of a network of logistics hubs within urban areas for designated daily time intervals
and handcart last-mile deliveries. The objective of the study is the development of a
mathematical programming model for identifying the optimal number and locations of
hubs for serving demand with the minimum cost, as well as the optimal times during the
day for leasing the facilities, while also allocating hubs to customers. The problem is
effectively solved by applying a Lagrangian relaxation and subgradient optimization
approach. Numerical examples and a sensitivity analysis provide evidence of the
robustness of the model and its ability to be effectively applied to address real problems.

Following September 11, 2001, numerous security policies have been created
which have caused a number of unique challenges in planning for the transportation
networks. In particular, there is a need to enhance security by improving collaboration
between various transportation modes. The transportation modes are disconnected
and have unequal levels of security and efficiency. Tools need to be refined for
collaboration and consensus building to serve as catalysts for efficient transportation
solutions. In this study, we developed and investigated a mathematical model using
Data Envelopment Analysis (DEA) to assess the safety and security of intermodal
transportation facilities. The model identifies the best and worst performers by
assessing several safety and security-related variables. The DEA model can assess the
efficiency level of safety and security of intermodal facilities and identify potential
solutions for improvement.

Traffic congestion is one of the most concerning issues in the transportation system. Recurrent congestion and non-recurrent congestion are explored in this research. This research will investigate one of the most concerning issues with the transportation system, congestion, using an overall delay analysis study. A developed fused database program was used to access and analyze the complete database data. Two online databases were used for obtaining traffic, incident and weather data. Eleven different scenarios such as peak-hours, rain scenario, incidents scenario, and work zone scenario were developed for the analysis. An overall delay study was performed on all
scenarios to find the impact recurring and non-recurring congestion on the highway. The results of this research were interesting for future adjustment and improvements on the two segments of highways selected.

The huge financial and societal cost associated with traffic crashes and the fact
that more than half of them occur at junctions, revealed the need for further research in
the field of junction safety. This research aims to investigate the quantitative impact of
junctions in relation to other selected parameters, on the frequency of road crashes in
urban areas in the State of Florida. Mathematical models were developed with the use of
loglinear analysis method for different traffic volumes in and out of junction. In addition,
sensitivity analysis was performed in order to better understand the impact of selected
parameters to the total number of crashes. The analysis has led to several conclusions
such as that angle and left turn collisions have much higher probability of occurrence at
junctions and that crashes which occur at junctions are much more probable for low and
medium volumes compared to no-junctions.

Traditional intersections have always caused congestion, delay, and accidents.
There are numerous geometric intersection designs that best fit each situation. This study
performed an operational and safety comparison with unsignalized/signalized offset, Tintersections, a two-lane roundabout, and a modified roundabout to decrease the overall
travel delay and increase the safety using a case study. Using data from a government source, all designs were tested in a calibrated micro simulation model and traffic signals were optimized using a signal optimization platform. Each design was tested with various balancing schemes, left turn percentages, and hourly volumes to determine the failure point. The unsignalized/signalized offset T-intersections, two-lane roundabout, and
modified roundabout were compared by throughputs, travel delay, and travel time. After
analysis, it was determined that the modified roundabout performed the best out of any design. All approaches had minimum travel delay while reducing the number of conflict
points considerably with the modified roundabout.