The work traces the early history of the Texas State Department of Highways. Beginning with the first efforts to create a department, the study focuses on the period between 1917 and 1923. Much attention goes to the legislative background of the early actions of the department. Subsequently, the work examines various statistical measures of the department's performance. This includes comparisons between Texas and nearby states, and the national highs, lows, and averages. Concluding the study is an examination of the department's immediate goals and long range plans in the years after 1923. The general conclusion of the study is that the department played a useful role in the development of state roads in Texas.

Vehicular communication is the enabling technology for the development of the intelligent transportation systems (ITS), which aims to improve the efficiency and safety of transportation. It can be used for a variety of useful applications such as adaptive traffic control, coordinated braking, emergency messaging, peer-to-peer networking for infotainment services and automatic toll collection etc... Accurate yet simple models for vehicular networks are required in order to understand and optimize their operation. For reliable communication between vehicles, the spectrum access is coordinated via carrier sense multiple access (CSMA) protocol. Existing models either use a simplified network abstraction and access control scheme for analysis or depend on simulation studies. Therefore it is important to develop an analytical model for CSMA coordinated communication between vehicles. In the first part of the thesis, stochastic geometry is exploited to develop a modeling framework for CSMA coordinated inter-vehicle communication (IVC) in a multi-lane highway scenario. The performance of IVC is studied in multi-lane highways taking into account the inter-lane separations and the number of traffic lanes and it is shown that for wide multi-lane highways, the line abstraction model that is widely used in literature loses accuracy and hence the analysis is not reliable. Since the analysis of CSMA in the vehicular setting makes the analysis intractable, an aggressive interference approximation and a conservative interference approximation is proposed for the probability of transmission success. These approximations are tight in the low traffic and high traffic densities respectively. In the subsequent part of the thesis, the developed model is extended to multi-hop IVC because several vehicular applications require going beyond the local communication and efficiently disseminate information across the roads via multi-hops. Two well-known greedy packet forwarding schemes are studied, that impose different tradeoffs between per-hop transmission success probability and forward packet progress, namely, the most forward with fixed radius (MFR) and the nearest with forward progress (NFP). In particular, a tractable and accurate modeling framework is developed to characterize the per-hop transmission success probability and the average forward progress for vehicular networks in a multi-lane highway setup. The developed model reveals the interplay between the spectrum sensing threshold of the CSMA protocol and the packet forwarding scheme. A new performance metric is defined, denoted as the aggregate packet progress (APP), which is a dimensionless quantity that captures the tradeoffs between the spatial frequency reuses efficiency, the per-hop transmission success probability, and the per-hop forward progress of the packets. To this end, in contrary to existing studies, the results show that with the proper manipulation of CSMA threshold, the MFR achieves the highest APP.

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With the progress and expansion of civilization, companies are interested in distributing their products and goods in distributed areas on a daily basis. These daily tasks are considered to ensure that the products reach the largest possible number of people to keep pace with accommodating the expansion and population. However, these daily duties demand a lot of effort and are financially burdened on both drivers and companies as well. Besides that, daily transportation might cause traffic congestion as well as being negative on the environment with harmful emissions coming from heavy-duty trucks. With overcrowding, companies may face delays in the arrival of their products to their customers, which is a point that may reflect negatively on the company's reputation in the business. One of the proposed solutions for companies to deal with these problems is to create a platoon of trucks during their transportation between the pickup stations and the drop-off stations. The literature review demonstrates that there are written benefits for the truck platoons, however, there is a lack of showing these benefits in the reality. The platoon simulation was built in this thesis to present the results numerically so that they could be contrasted with scenarios where the platoon was not used for freight transportation. This thesis focused on the benefits of a platoon from three aspects: the aspect of saving time, reducing cost by reducing fuel usage, and finally increasing safety in public driving on highways. The results of using the simulations showed that the time was using to deliver the goods by using truck platoons was shorter than the time by using individual trucks. Additionally, traffic congestion was less when the trucks were driven on single-lane on highways, which causes reduced the number of accidents especially, those that occurred with small cars. They compiled accident data between 2007 and 2017, coming to the conclusion that 98,790 crashes involving large trucks were among the 243,017 total crashes. In the same survey, the authors found that 9.4% of truck accidents occurred when changing lanes with small cars on highways. This thesis demonstrated numerically that there was less fuel usage while the trucks were driven in a platoon compared with the fuel usage of the trucks that were driven individually. In a word, transportation companies will gain benefits from using truck platoons to deliver their goods to their customers.

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Innovation is a popular topic that receives significant attention from both organizations and academics. This attention includes scholars, executives, public entities, and private organizations in the construction and infrastructure fields. Scholars have examined innovation in both construction and public-private partnerships (P3s). Despite this work, gaps remain – particularly regarding the impact of project-level factors on technical innovation in P3s. Hence, this dissertation contributes to the areas of infrastructure innovation and P3s using a three pronged approach. First, exploration of the literature identified 348 factors that drive or inhibit innovation in infrastructure projects. These factors were synthesized into 33 aggregate factors such as client, integration, and risk. Subsequently, case interviews with practitioners revealed 110 factors that influence innovation in P3 projects; these were further grouped into six main categories. Literature and practitioner perspectives were strongly aligned around four predominant factors influencing innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level innovation was derived and tested using deviations from project baselines submitted as alternative technical concepts (ATCs) in four infrastructure project procurements. The developed framework provides the infrastructure and construction community with a replicable approach to assess technical enhancements in projects to determine whether they are innovative or not and if so the type of innovation. Application of the framework classified only 7 of 53 ATCs from the four projects as innovative. However, the remainder added significant value through cost savings, improved safety or operational efficiency. Lastly, a case study of six contemporary US highway P3 projects: i) Elizabeth River Tunnels in Virginia; ii) East End Crossing in Indiana; iii) North Tarrant Expressway segments 3A&B in Texas; iv) I-4 Ultimate Improvement in Florida; v) I-77 HOT Lanes in North Carolina; and vi) SH 288 Toll Lanes in Texas was conducted to determine the types of innovation found and to assess the influence of key project characteristics on P3 technical innovation. Technical enhancements proposed by concessionaires were assessed using project documentation and semi-structured interviews with 23 experienced public and private sector project participants. Innovations were uncovered, albeit limited. Procurement, project type, and payment mechanism (demand risk/traffic risk) were the key project characteristics influencing innovation. Further, these same characteristics promoted added-value in the form of increased safety, reduced project durations, and decreased project costs. Together, the three studies advance our understanding of the effect of project attributes on technical innovation and value creation in infrastructure public-private arrangements. / Ph. D. / Governments around the world are using public-private partnerships (P3s) to provide needed infrastructure. They often claim that the involvement of the private sector in the delivery of infrastructure will generate various benefits, particularly innovation. However, public agencies and private infrastructure developers provide limited evidence of innovation outcomes. While academic scholars have explored the topic, the studies are limited and have generated alternative results. This dissertation contributes to the areas of infrastructure innovation and P3s with three independent but interrelated studies. First, the exploration of the literature and the perspectives of 23 experienced project participants identified four predominant factors that influence the occurrence of innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level technical innovations in a replicable and transparent manner was developed and tested. Lastly, a multi-case study approach was adopted to determine the types of innovation found and to assess the influence of key project characteristics on P3 project technical innovation. Project documentation was assessed and interviews were conducted with public and private participants in six contemporary US highway P3 projects. Technical innovation was found within the cases, albeit limited. Demand risk and involving the private partner early were two of the most influential project characteristics on technical innovation. Further, these two characteristics promoted added-value technical enhancements through increased safety, reduced project durations, and decreased project costs.

Innovation is a popular topic that receives significant attention from both organizations and academics. This attention includes scholars, executives, public entities, and private organizations in the construction and infrastructure fields. Scholars have examined innovation in both construction and public-private partnerships (P3s). Despite this work, gaps remain — particularly regarding the impact of project-level factors on technical innovation in P3s. Hence, this dissertation contributes to the areas of infrastructure innovation and P3s using a three pronged approach. First, exploration of the literature identified 348 factors that drive or inhibit innovation in infrastructure projects. These factors were synthesized into 33 aggregate factors such as client, integration, and risk. Subsequently, case interviews with practitioners revealed 110 factors that influence innovation in P3 projects; these were further grouped into six main categories. Literature and practitioner perspectives were strongly aligned around four predominant factors influencing innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level innovation was derived and tested using deviations from project baselines submitted as alternative technical concepts (ATCs) in four infrastructure project procurements. The developed framework provides the infrastructure and construction community with a replicable approach to assess technical enhancements in projects to determine whether they are innovative or not and if so the type of innovation. Application of the framework classified only 7 of 53 ATCs from the four projects as innovative. However, the remainder added significant value through cost savings, improved safety or operational efficiency. Lastly, a case study of six contemporary US highway P3 projects: i) Elizabeth River Tunnels in Virginia; ii) East End Crossing in Indiana; iii) North Tarrant Expressway segments 3AandB in Texas; iv) I-4 Ultimate Improvement in Florida; v) I-77 HOT Lanes in North Carolina; and vi) SH 288 Toll Lanes in Texas was conducted to determine the types of innovation found and to assess the influence of key project characteristics on P3 technical innovation. Technical enhancements proposed by concessionaires were assessed using project documentation and semi-structured interviews with 23 experienced public and private sector project participants. Innovations were uncovered, albeit limited. Procurement, project type, and payment mechanism (demand risk/traffic risk) were the key project characteristics influencing innovation. Further, these same characteristics promoted added-value in the form of increased safety, reduced project durations, and decreased project costs. Together, the three studies advance our understanding of the effect of project attributes on technical innovation and value creation in infrastructure public-private arrangements. / PHD / Governments around the world are using public-private partnerships (P3s) to provide needed infrastructure. They often claim that the involvement of the private sector in the delivery of infrastructure will generate various benefits, particularly innovation. However, public agencies and private infrastructure developers provide limited evidence of innovation outcomes. While academic scholars have explored the topic, the studies are limited and have generated alternative results. This dissertation contributes to the areas of infrastructure innovation and P3s with three independent but interrelated studies. First, the exploration of the literature and the perspectives of 23 experienced project participants identified four predominant factors that influence the occurrence of innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level technical innovations in a replicable and transparent manner was developed and tested. Lastly, a multi-case study approach was adopted to determine the types of innovation found and to assess the influence of key project characteristics on P3 project technical innovation. Project documentation was assessed and interviews were conducted with public and private participants in six contemporary US highway P3 projects. Technical innovation was found within the cases, albeit limited. Demand risk and involving the private partner early were two of the most influential project characteristics on technical innovation. Further, these two characteristics promoted added-value technical enhancements through increased safety, reduced project durations, and decreased project costs.