bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Analysis of Explosive Welded Ti-Cr/Ni Steel in As-Received State and after Heat Treatment Using Synchrotron/ Analiza Fazowa Połączenia Ti-Cr/Stali Ni Wytworzonego Metodą Zgrzewania Wybuchowego W Stanie Wyjściowym Oraz Po Obróbce Termicznej Z Wykorzystaniem Promieniowania Synchrotonowego
Authors: Ostroushko D. , Mazancová E. , Saksl K. , Milković O.
Published: February 2015

Surface coatings protection is one of the most important processes ensuring efficient and economic use of basic materials, mostly of lower-quality. At interface of clad and basic material intermetallic phases are formed, representing quite different matrix with dissimilar properties unlike the welded materials. One type of surface coating is explosive bonding which belongs to group of pressure welding. The work is focused on interface shape line, inhomogeneities in vicinity of the wave joint both in basic material and in vicinity of weld line of the Ti and Cr/Ni stainless steel (SS) matrix. Investigated weld was both in as-received state and after heat treatment carried out at 600°C/90 minutes/air. Presented phases have been identified using X-ray diffraction performed by synchrotron. The Tiα, Fe-fcc, Fe-bcc and intermetallic phases Fe2Ti were detected at interface area.
Diffusion Kinetics in Explosive Cladding of Dissimilar Alloys as Described through the Miedema Model/ Kinetyka Procesu Dyfuzji W Układach Platerów Wytwarzanych Z Wykorzystaniem Energii Wybuchu, Na Bazie Stopów O Silnie Odmiennych Właściwościach, Opisanych Modelem Miedema
Authors: Saravanan S. , Raghukandan K.
Published: February 2015

Explosive cladding of dissimilar plates is achieved by the intensive deformation occurring at high pressure and temperature generated from the detonating explosive at the collision interface. The interface morphology, with its characteristic undulations, is dictated by the extent of kinetic energy spent at the mating interface. Nevertheless, the inter-metallic compound formation at the mating interface weakens the joint. The prediction of the probability of inter-metallic formation at aluminum-SS 304, copper-SS 304 and titanium-SS 304 explosive cladding interfaces is attempted in this study by employing Miedema model. Granular explosives (detonation velocity: 4000 m/s) and parallel plate combination were employed with uni-loading ratio (standoff distance-5 mm). The influence of chemical energy in determining the bond strength of explosive clads is discussed as well.
Designing and Manufacturing of Explosion Chambers for Scientific Research and Explosive Working of Materials/ Projekt I Wytworzenie Komory Do Detonacyjnej Dla Celów Naukowych Oraz Przeprowadzenie Zgrzewania Wybuchowego Dla Materiałów Metalicznych
Authors: Shtertser A. , Stoyanovskii O. , Zlobin B. , Meshcheryakov Y. , Skornyakov Y.
Published: February 2015

The paper presents the experience in designing and manufacture of explosion chambers for researching purposes and technological applications gathered in Lavrentyev Institute of Hydrodynamics of Siberian Branch of Russian Academy of Sciences. The peculiarity of the developed explosion chambers is that they are all-metal units with a long service life (10 thousand explosions and more); they completely isolate blast effects (shock wave, seismic wave, etc.) and hence can be installed in laboratory rooms and industrial premises and, when necessary, can be disassembled and moved to a new place of exploitation. Presented examples illustrate the application of the explosion chambers in production of new materials, articles, and for elimination of ammunition.
Welding of Thermomechanically Rolled Fine-Grain Steel by Different Types of Lasers/ Spawanie Stali Drobnoziarnistej Walcowanej Termomechanicznie Laserami Różnego Typu
Authors: Lisiecki A.
Published: February 2015

The autogenous laser welding of 2.5 mm thick butt joints of thermomechanically rolled fine-grain steel grade S420MC was investigated. Butt joints were laser welded by the Yb:YAG Disk laser, emitted a circular laser beam with spot diameter of 200 μm at 1.03 μm wavelength, and also by the high power direct diode laser, emitted a rectangular beam with dimension of 1.8x6.8 mm at 808 nm wavelength. Different welding modes were identified for the lasers applied. The conduction welding mode was observed in whole of the diode laser welding parameters. While high quality joints, without any internal defects and characterized with satisfactory mechanical performance were produced in a wide range of parameters. The butt joints produced by Disk laser were welded at keyhole mode. In this case a slight tendency to weld porosity was found.
Nanobainitic Structure Recognition and Characterization Using Transmission Electron Microscopy/ Rozpoznawanie I Charakteryzacja Struktury Nanobainitycznej Za Pomocą Transmisyjnej Mikroskopii Elektronowej
Authors: Jezierska E. , Dworecka J. , Rozniatowski K.
Published: February 2015

Various transmission electron microscopy techniques were used for recognition of different kinds of bainitic structures in 100CrMnSi6-4 bearing steel. Upper and lower bainite are morphologically different, so it is possible to distinguish between them without problem. For new nanobainitic structure, there is still controversy. In studied bearing steel the bainitic ferrite surrounding the retained austenite ribbon has a high density of dislocations. Significant fragmentations of these phases occur, bainitic ferrite is divided to subgrains and austenitic ribbons are curved due to stress accommodation.
Characterization of Nanobainitic Structure Obtained in 100Crmnsi6-4 Steel after Industrial Heat Treatment/ Charakteryzacja Struktury Nanobainitycznej Wytworzonej W Handlowej Stali Łożyskowej – 100Crmnsi6-4 W Przemysłowej Obróbce Cieplnej
Authors: Dworecka J. , Jezierska E. , Rozniatowski K. , Swiatnicki W.
Published: February 2015

The aim of the work was to produce a nanobainitic structure in the commercial bearing steel - 100CrMnSi6-4 and to characterize its structure and mechanical properties.

In order to produce this structure the austempering heat treatment was performed, with parameters that have been selected on the basis of dilatometric measurements of phase transformation kinetics in steel. The heat treatment process was performed in laboratory as well as in industrial furnaces. The obtained structure was characterized using transmission electron microscopy. In order to investigate the effect of the microstructure parameters on the material’s mechanical properties, the hardness, impact strength and static tensile tests have been conducted.
Microstructural Features of Strain-Induced Martensitic Transformation in Medium-Mn Steels with Metastable Retained Austenite/ Cechy Mikrostrukturalne Indukowanej Odkształceniem Przemiany Martenzytycznej W Stalach Sredniomanganowych Z Metastabilnym Austenitem Szczątkowym
Authors: Grajcar A. , Kilarski A. , Radwanski K. , Swadzba R.
Published: February 2015

The work addresses relationships between the microstructure evolution and mechanical properties of two thermomechanically processed bainitic steels containing 3 and 5% Mn. The steels contain blocky-type and interlath metastable retained austenite embeded between laths of bainitic ferrite. To monitor the transformation behaviour of retained austenite into strain-induced martensite tensile tests were interrupted at 5%, 10%, and rupture strain. The identification of retained austenite and strain-induced martensite was carried out using light microscopy (LM), scanning electron microscopy (SEM) equipped with EBSD (Electron Backscatter Diffraction) and transmission electron microscopy (TEM). The amount of retained austenite was determined by XRD. It was found that the increase of Mn addition from 3 to 5% detrimentally decreases a volume fraction of retained austenite, its carbon content, and ductility.
Interpretations of Cooling Dilatograms in the Range of the Bainitic and Martensitic Transformations/ Intwerpretacja Dylatogramów Chłodzenia W Zakresie Przemiany Bainitycznej I Martenzytycznej
Authors: Pacyna J.
Published: February 2015

The method of interpretation of cooling dilatograms of undercooled austenite during its transformation into upper and lower bainite (UB and LB) and into martensite (M), applied in the Laboratory of Phase Transformations of AGH University of Science and Technology in Krakow, is presented in the hereby paper. The relation of the mechanism of the mentioned above transformations to places on the dilatometric curve where transformations start and where they are continued was indicated. An appeal for the unified, correct interpretation of dilatograms of phase transformations, in all laboratories of the world, was formulated. This will allow the formation of equally accurate diagrams of the kinetics of phase transformation of undercooled austenite at its continuous cooling (CCT). In consequence, this could provide a development of more advanced heat treatment technologies. Such approach will also allow for the correct assessment of the influence of the alloying elements on the stability of austenite and phase transformation temperatures at its cooling.
Microstructure and Properties of Surface Layer of Carburized 38CrAlMo6-10 Steel Subjected to Nanostructurization by a Heat Treatment Process/ Struktura I Właściwości Warstwy Naweglanej Na Stali 38Cralmo6-10 Po Procesie Nanostrukturyzacji W Warunkach Obróbki Cieplnej
Authors: Wasiluk K. , Skołek E. , Swiatnicki W.
Published: February 2015

The aim of the study was to produce and characterize a nanobainitic microstructure in surface layers of carburized 38CrAlMo6-10 structural steel. Steel contained 1.% Al and 0.3% Si - elements hindering the cementite precipitation, which was considered to be adequate for obtaining a carbide free bainite. Steel samples were subjected to two different vacuum carburizing processes in order to obtain two different contents of carbon in surface layer. To produce a nanobainitic microstructure a heat treatment consisting of austempering at temperature slightly higher than the martensite start temperature (Ms) of the layer was applied after each carburization process. It was found, that the obtained microstructure of carburized layer depends strongly on carbon content. In steel with surface layer containing lower carbon content a nanobainitic microstructure with carbon-enriched residual austenite was formed. In case of surface layer containing higher carbon content the ultra-fine grained lower bainite was obtained.
Thermomechanically Rolled Medium-Mn Steels Containing Retained Austenite/ Walcowane Termomechanicznie Stale Średniomanganowe Zawierające Austenit Szczątkowy
Authors: Grajcar A. , Skrzypczyk P. , Wozniak D.
Published: February 2015

Chemical composition of four medium-Mn steels containing a various Mn content (3 and 5%) have been proposed in the present work. The two steels are base steels whereas the other two contain Nb microaddition. Thermomechanical rolling tests of 3.3 mm sheets have been carried out using a semi-industrial hot strip rolling line. Detailed investigations of the identification of structural constituents using light microscopy and scanning electron microscopy techniques have been performed. X-ray method has been applied to determine an amount of retained austenite and its C content. Significant microstructural parameters were revealed using an EBSD technique. It was found that the Mn addition affects strongly a microstructure type, stability of retained austenite and mechanical properties determined with a static tensile test. The steels containing 3% Mn are characterized by a good combination of strength and ductility whereas the tensile strength up to 1300 MPa is possible to obtain for the higher Mn content steels.
Microstructure and Mechanical Properties of Structural Steel after Dynamic Cold Working Deformation/ Wpływ Dynamicznego Odkształcenia Plastycznego Na Zimno Na Mikrostrukturę I Własności Stali Konstrukcyjnej
Authors: Pacyna J. , Dabrowski R. , Rozniata E. , Kokosza A. , Dziurka R.
Published: February 2015

The results of the selected mechanical properties i.e. ultimate tensile strength (UTS), yield stress (YS), elongation (EL), reduction of area (RA), hardness (HV) and impact strength (KCV) of the common, S235JR grade steel, are presented in the paper. A strong relationship between the above mentioned properties and cooling rates after hot rolling of rods, made of this steel, was found.

Additionally, the possibility of further enhancing of mechanical properties (UTS and YS) by the controlled, dynamic cold working, was shown. The use of such deformation, through changes in the microstructure allows for the upper yield stress (YS) increase - app. 10% and ultimate tensile strength UTS - app. 5%.

Simultaneously, very high indicators of plasticity (EL, RA) and impact strength (KCV) are retained, as they were immediately after the rolling. The possibility of improving the mechanical properties of rods made of this steel grade has a great technological and commercial importance for its manufacturers, as well as for their final users.
The Application of Neural Networks for Studying Phase Transformation by the Method of Acoustic Emission in Bearing Steel/ Zastosowanie Sieci Neuronowych Do Badania Przemian Fazowych W Stali Łożyskowej Metodą Emisji Akustycznej
Authors: Wozniak T.Z. , Ranachowski Z. , Ranachowski P. , Ozgowicz W. , Trafarski A.
Published: February 2015

The research was carried out on steel 100CrMnSi6-4 under isothermal austempering resulting in forming the duplex structure: martensitic and bainitic. The kinetics of transformation was controlled by the acoustic emission method. Complex phase transformations caused by segregation and carbide banding occur at the low-temperature heat treatment of bearing steel. At the temperature close to MS, a certain temperature range occurs where an effect of the first product of prior athermal martensite on the bainitic transformation can be observed. In the registered signal about 15 million various events were registered. There were considered three types of acoustic emission events (of high, medium and low energy), with relatively wide sections and with different spectral characteristics. It was found that the method of acoustic emission complemented by the application of neural networks is a sensitive tool to identify the kinetics of bainitic transformation and to show the interaction between martensitic and bainitic transformations.
Hollow waveguides as polarization converting elements: a theoretical study
Authors: Helfert S. F. , Edelmann A. , Jahns J.
Published: February 2015

Subwavelength apertures in a metallic film act as hollow waveguides. By using a non-quadratic cross-section, an anisotropic transmission behaviour results for the two polarization states. Thus, an array of metallic subwavelength apertures may be used as polarization converter, e.g., as a half-wave plate. By varying orientation and shape of the cross-sections locally, one can design polarization shifting elements for complex wave fields. Here, we present a theoretical consideration on the physical properties and compare with dielectric form birefringence.
Optical amplification and stability of spiroquaterphenyl compounds and blends
Authors: Fuhrmann-Lieker T. , Lambrecht J. , Hoinka N. , Kiurski M. , Wiske A. , Hagelstein G. , Yurttagü N. , Abdel-Awwad M. , Wilke H. , Messow F. , Hillmer H. , Salbeck J.
Published: February 2015

In this contribution, we present a systematic investigation on a series of spiroquaterphenyl compounds optimised for solid state lasing in the near ultraviolet (UV). Amplified spontaneous emission (ASE) thresholds in the order of 1 μ/cm2 are obtained in neat (undiluted) films and blends, with emission peaks at 390±1 nm for unsubstituted and meta-substituted quaterphenyls and 400±4 nm for para-ether substituted quaterphenyls. Mixing with a transparent matrix retains a low threshold, shifts the emission to lower wavelengths and allows a better access to modes having their intensity maximum deeper in the film. Chemical design and blending allow an independent tuning of optical and processing properties such as the glass transition.
Impact of Highway Investment on the Economy and Employment across U.S. Industrial Sectors
Authors: He Xiang , Kastrouni Eirini , Zhang Lei
Published: February 2015

This study investigated the impact of highway investment on employment in the U.S. industrial sector. A separate simultaneous equations model was developed for each of the 23 industrial sectors covering the entire spectrum of economic activities to address the widely discussed issue of bidirectional causality between highway investment and economic growth. To consider the mechanism by which highway investment actually influenced economic performance, the authors modeled travel demand and highway supply jointly to reflect the level of transportation services. Travel demand plays an important role in the delivery of the effect of highway investment to economic output and employment; in the long run, this demand also affects decision making on highway investment. The models were estimated with a comprehensive panel of data collected over 29 years from 351 metropolitan statistical areas in the United States. The elasticity results suggest that highway investment stimulates economic growth and job creation. For instance, a 10% increase in total highway capacity would yield an annual $326 billion increase in the U.S. gross domestic product. In addition, this 10% increase in capacity is estimated to create approximately 1.5 million new jobs for the whole economy in the long run. However, the economic and employment effects vary across industrial sectors. The findings suggest that although the overall effect on jobs is positive, highway investment leads to employment growth in only 12 of the 23 industrial sectors. In particular, the retail trade, construction, manufacturing, and accommodation service sectors would benefit the most from highway investment.
Impact of Bus Rapid Transit and Metro Rail on Property Values in Guangzhou, China
Authors: Salon Deborah , Wu Jingyan (Dora) , Shewmake Sharon
Published: February 2015

An effective transport system can increase access and raise land values; thus, governments should be able to capture part of this price premium for transit access. These revenues could be used to fund further investments in public transit or other projects. Reliable measures of the price premium for transit access can help guide governments in setting policies to capture value. Guangzhou, China, has an extensive metro rail system and the highest-capacity bus rapid transit line in China. This study examines the effects of these two public transport systems on the prices of apartments in the city by using a unique set of data collected from a mainstream Chinese real estate website. Ordinary least squares, spatial regression models, and quantile hedonic regression were used to estimate the price premium for transit access. The findings suggest that proximity to the metro and the bus rapid transit line has a substantial and statistically significant effect on apartment prices that varies by district and the amenities provided.
Travel Behavior of the Poor after Welfare Reform
Authors: Blumenberg Evelyn , Thomas Trevor
Published: February 2015

In 1996, President Bill Clinton signed into law the Personal Responsibility and Work Opportunity Reconciliation Act, also known as welfare reform. As part of this act, Congress established welfare block grant programs that included a set of provisions intended to promote employment. In the aftermath of these reforms, policy makers turned to transportation as one strategy to transition welfare recipients and other low-income adults rapidly into the labor market. As the foundation for these transportation programs, studies documented the travel patterns of the poor and highlighted the limited access of these individuals to automobiles. Given the many changes since the 1990s, it is time to revisit these data. This study draws on the 1995 Nationwide Personal Transportation Survey and the 2009 National Household Travel Survey to examine changes in the commute travel of low-income adults since welfare reform. The data provide evidence that the reliance on automobiles has increased significantly over time; the growth reflects the many advantages of cars in increasingly decentralized environments. However, some population groups—particularly the carless—have become more dependent on public transit to access work. These findings suggest the importance of protecting and expanding vital transit services for those who need them, as well as acting on behalf of low-income households that may be better served through personal vehicular travel.
Impact of Attitudes and Life Stage on Decline in Rates of Driver's License Acquisition by Young People in Melbourne, Australia
Authors: Delbosc Alexa , Currie Graham
Published: February 2015

In recent decades, young adults in North America, Australia, and much of Europe have become less likely to obtain a driver's license. Research into this trend is only recently emerging, yet it is likely to have important impacts on public transport and road planning. Little is known about the attitudes of young adults toward cars and driving and how these attitudes affect the decision of whether to acquire a driver's license. This paper presents the results of a survey of more than 200 young adults in Melbourne, Australia. The survey explores the relationship between possession of a driver's license and demographics, life stage, use of social media, and attitudes, as well as the reasons why some young adults do not have a driver's license. Although most young adults find that a car provides independence, they also see it as a big responsibility; they are much less likely to equate a car with success in life. Nondrivers say that they would rather spend money on other expenses and believe that they can get where they want to go without driving. The policy implications of the results are discussed, and future research directions are suggested.
Workplace Neighborhoods, Walking, Physical Activity, Weight Status, and Perceived Health
Authors: Forsyth Ann , Oakes J. Michael
Published: February 2015

Recent interest has focused on how the built environment in residential neighborhoods affects walking and other physical activity. The neighborhood around the workplace has been examined far less. This study explored the neighborhood around the workplace and its correlation with the amount of walking, level of physical activity, body mass index, and perceived health of those who (a) worked away from home (N = 446) and (b) were retired or unemployed (N = 207). Study participants were recruited from environmentally diverse residential neighborhoods in the Minneapolis–Saint Paul, Minnesota, metropolitan area in 2004. Participants wore an accelerometer, kept a travel diary, and answered a survey. The workplace neighborhood environments were measured with a geographic information system. In bivariate assessments, many features of the workplace neighborhood environment were significantly, but modestly, correlated with walking for travel, including density, street pattern, and land use (commercial, office, and residential). Fewer environmental features were correlated with total physical activity, a result confirmed in multivariate analyses. Although several workplace neighborhood environmental variables were correlated with total walking, relevant to the field of transportation, the pattern of association with total physical activity was not as consistent or strong. Because many people spend a considerable amount of time at work, more research is needed on this topic.
Dispersion Modeling of Traffic-Related Air Pollutant Exposures and Health Effects among Children with Asthma in Detroit, Michigan
Authors: Batterman Stuart , Ganguly Rajiv , Isakov Vlad , Burke Janet , Arunachalam Saravanan , Snyder Michelle , Robins Thomas , Lewis Toby
Published: February 2015

Vehicular traffic is a major source of ambient air pollution in urban areas. Traffic-related air pollutants, including carbon monoxide, nitrogen oxides, particulate matter less than 2.5 μm in diameter, and diesel exhaust emissions, have been associated with adverse human health effects, especially in areas near major roads. In addition to emissions from vehicles, ambient concentrations of air pollutants include contributions from stationary sources and background (or regional) sources. Although dispersion models have been widely used to evaluate air quality strategies and policies and can represent the spatial and temporal variation in environments near roads, the use of these models in health studies to estimate air pollutant exposures has been relatively limited. This paper summarizes the modeling system used to estimate exposures in the Near-Roadway Exposure and Urban Air Pollutant Study, an epidemiological study that examined 139 children with asthma or symptoms consistent with asthma, most of whom lived near major roads in Detroit, Michigan. Air pollutant concentrations were estimated with a hybrid modeling framework that included detailed inventories of mobile and stationary sources on local and regional scales; the RLINE, AERMOD, and CMAQ dispersion models; and monitored observations of pollutant concentrations. The temporal and spatial variability in emissions and exposures over the 2.5-year study period and at more than 300 home and school locations was characterized. The paper highlights issues with the development and understanding of the significance of traffic-related exposures through the use of dispersion models in urban-scale exposure assessments and epidemiology studies.
Peak Vehicle Miles Traveled and Postpeak Consequences?
Authors: Polzin Steven E. , Chu Xuehao
Published: February 2015

The purpose of this paper is twofold: first, to summarize changes in travel that account for the decline in total roadway vehicle travel from the previous decade's peak levels and, second, to speculate on the implications of postpeak vehicle miles traveled trends. Both sections of the paper are speculative. The lack of available data makes it difficult to diagnose fully the changes in travel behavior that result in lower levels of roadway travel. Planners are only beginning to think about the impacts of no growth in roadway travel. The paper evaluates travel trends, by addressing freight versus passenger travel, urban versus rural, mode choice, age, income, communication substitution, and logistics as factors affecting vehicle miles traveled. Consequences include transportation capacity requirements, transportation infrastructure productivity, induced demand, transportation land use, transportation and economic development, challenges for traditional planning processes, equity implications, and risk and uncertainty.
Supply Chain–Consistent Threshold Accessibility Measures for Megaregion Economic Development
Authors: Vadali Sharada , Chandra Shailesh
Published: February 2015

Supply chain networks (comprising buyer–supplier connections) are integral to specialized manufacturing industries and are vital to the growth and development of megaregions. Transportation planning in mega-regions requires an understanding of specialized industry sectors and the enhancement of the effects of the business network. Positive externalities and a competitive advantage can be augmented through transportation interventions. The directness of linkages and enhanced access between buyers and suppliers in any production network enables agglomeration economies, maximizes returns from investments, and can contribute to industry competitiveness. Physical transport networks are vital in ensuring directness in manufacturing sectors in which value chain segments are separated physically. This paper presents a framework for a behaviorally consistent directness measure explicitly linked to transportation infrastructure in megaregions, characterized by supply chains that enhance business networks. This index measures the enhanced accessibility provided by transportation by allowing systematic identification of links between buyers and suppliers in the value chain. The paper illustrates how the measure may be analyzed for an automobile manufacturing chain that is part of the southeastern Piedmont Atlantic megaregion.
Managing the Indirect Impacts of Bypasses on Small and Medium-Sized Communities in Florida
Authors: Seggerman Karen , Williams Kristine
Published: February 2015

In Florida, the bypass alternative is increasingly being considered in small and medium-sized communities that contain roadways that are part of Florida's strategic intermodal system (SIS)–-roadways critical to the statewide movement of people and goods. These roads are often the primary roadways into and through smaller communities. Local governments sometimes seek SIS designation to gain funding for increasing the capacity or improving the function of the major roadway; this process leads to consideration of a bypass. Observed issues with these bypasses include the following: ( a) the SIS designation assigns level of service and design criteria that increase pressure for a bypass alternative; ( b) misconceptions abound regarding potential positive and negative impacts of a bypass; ( c) inadequate consideration is given to evaluation of the potential indirect impacts of a bypass on land use and related issues (e.g., livability, local mobility); ( d) without local roadway network planning in affected areas, many local trips are likely to rely on the new bypass; ( e) access management is critical for the bypass and along major roadways accessing the bypass and their interchanges; ( f) the bypassed roadway may be oversize in relation to local mobility needs and could benefit from multimodal enhancements; and ( g) proactive attention is needed for addressing potential indirect land use and mobility impacts, which will help determine appropriate plans, strategies, and mitigation measures. This paper examines these issues and offers practical enhancements to current policy and practice to help the Florida Department of Transportation and local governments achieve a multidimensional approach to bypass planning and impact mitigation.
Expanding a Municipal Bikeshare System into an Urban National Park through Community Partnerships
Authors: Sherwood Krista , Murphy Julia
Published: February 2015

San Antonio Missions National Historical Park is in the urban outskirts of downtown San Antonio, Texas. Since the mission was established as a National Park Service site, visitors have arrived at the park primarily by personal vehicle. Reducing the number of motorized vehicles near the historic missions and promoting alternative transportation options for visitors will help protect resources and enhance the visitor experience. The first bikesharing system in Texas, San Antonio B-Cycle, was launched in 2011 in downtown San Antonio. Shortly afterward, partners in the city of San Antonio's Office of Sustainability, San Antonio Bike Share, and the National Park Service's Rivers, Trails, and Conservation Assistance program proposed a linear expansion of the bikeshare system from downtown, south along the San Antonio River and a newly built recreation trail, to connect to the park. A successful project proposal was developed for an FTA grant; in 2012 the city was awarded $324,000 and the following year received an additional $295,774. This case study documents the process for expanding the San Antonio urban municipal bikeshare system in a nontraditional linear way, within a national park, by leveraging community partnerships. The study presents contextual information on the local setting and its transportation challenges, identifies relevant strategic initiatives prompting citywide improvements, summarizes the bikesharing concept, and details project development steps. The study concludes with analysis of usage data, which indicates project success and distills project challenges and key findings into a useful tool for other bikeshare implementation or expansion efforts.
Transportation Scholars
Authors: Villwock-Witte Natalie , Newman Jason , Chesson Katherine
Published: February 2015

This paper presents a review of the National Park Foundation Transportation Scholars program, documenting its long-term positive effect on the National Park Service and the scholars. Case studies were made of three parks that had hosted a scholar. For each park, the final report created by the scholar was reviewed for recommendations made. Then interviews of park personnel were conducted to determine if the recommendations had been implemented. A survey of program alumni provided insight into the effect of the program on participants’ careers. Many scholar recommendations were implemented. However, the recommendations may not have been the most effective aspect of the program. Rather, fresh ideas, transportation-related expertise, enthusiasm for the project, and the ability to focus on transportation issues may be some of the significant program benefits to the parks. The results of the alumni survey showed that a majority held positions in a federal agency. Trends established this program as a conduit for young talent to work within a federal agency.
Opportunities for Programming Suburban Multimodal Transportation Retrofits through the Maintenance Program
Authors: Miller John S. , Ohlms Peter B.
Published: February 2015

Half of Virginia's population lives in a jurisdiction with fewer than 1,000 people per square mile. Low densities, segregated land uses, and a lack of multimodal infrastructure limit opportunities for non automobile transportation options. In those locations, the incorporation of nonautomobile modes into the capital programming process is difficult without dedicated funding sources, advocates who fully understand the programming schedule, and mechanisms with which to compare fairly the benefits of such investments with traditional highway investments. This paper examined an effort to bring one type of nonautomobile investment–-bicycle accommodations–-to a suburban corridor in metropolitan Richmond, Virginia, a location that would not otherwise appear conducive to alternative modes. The catalyst for considering bicycle accommodations was the maintenance process rather than the capital planning process. Five case study characteristics made this consideration feasible within the suburban context: ( a) information exchange between members of a county board of supervisors and the leadership of a state department of transportation; ( b) staff willingness to interpret recent design guidance carefully to adapt available infrastructure for use by other modes; ( c) a realization that the maintenance program yields an opportunity to implement new multimodal infrastructure; ( d) an ability to present multiple multimodal options, because any project development process consists of many decision points and a preferred option may later become infeasible; and ( e) robust consideration of findings from previous work that may influence the relative safety of possible options. Although the case study focused on bicycle accommodations, these characteristics may be of interest to others using the maintenance process to improve accommodations for other modes.
Incorporating Costs of Life-Cycle Impacts into Transportation Program Development
Authors: Hameed Faisal , Hancock Kathleen
Published: February 2015

Ensuring sustainability is necessary for balancing economic viability, the environment, and the social system. Because transportation infrastructure projects have direct and indirect impacts on this balance, transportation agencies must consider the sustainability and environmental impacts of transportation investment during the planning and programming phase. An integrated life-cycle analysis approach (ILCA2) that integrates life-cycle assessment and life-cycle cost analysis is developed through the establishment of a reasonable life-cycle time frame, representative elements, largely homogeneous transportation facilities with representative cross sections, and accepted construction, maintenance, and rehabilitation practices. The methodology quantifies life-cycle environmental impacts for the carbon footprint of materials in carbon dioxide equivalent, quantity of wasted materials, and quantity of stormwater runoff along with associated costs. The use of the ILCA2 is demonstrated for a case study of urban roadway projects in a sample transportation state transportation improvement plan. A case study shows that initial costs represent approximately 20% of life-cycle costs; environmental impact costs are higher than direct operational costs, energy costs, and resurfacing costs. The use of the ILCA2 for transportation programming allows decision makers to evaluate the larger impacts of transportation investments as well as provides opportunities for considering programmatic changes to practices that support sustainability.
Hidden Social Networks that Drive Online Public Involvement in Infrastructure Construction
Authors: Bakht Mazdak Nik , El-Diraby Tamer E.
Published: February 2015

Several studies have emphasized the role of social media in public involvement during planning, construction, and operation of infrastructure. Social media can offer optimal, bidirectional communication with the public and an efficient flow of information and feedback between decision makers and project end users. However, the underlying social networks formed in the background of public relations processes on online social media largely have been neglected. Such networks are referred to as infrastructure discussion networks (IDN) and can be rich sources of information for decision makers. If it can be proved that these networks follow the general behavior of social networks, then rich tools developed in social network analysis can be used to profile users and help decision makers study user attitudes. This paper compares the IDNs of four light rail transit projects in various cities in the United States and Canada and studies them under the microscope of social network analysis. The study shows that IDNs exhibit the general structure of social networks (such as small-world behavior, scale-free degree distribution, and high clustering). The IDNs also include meaningful communities, detection and evaluation of which could lead to more efficient offline and online public involvement processes. Given the recent trends in presence of infrastructure projects on online social media, the methods presented in this paper can be readily applied by practitioners to improve their public engagement practices.
Origins of Metropolitan Transportation Planning and the Urban Stakes of Interstate Highway Funding, 1956–1962
Authors: Deutsch Cheryl
Published: February 2015

Speaking before Congress in April 1962, President John F. Kennedy called for an overhaul of federal transportation programming. Heeding his call, Congress passed the 1962 Federal-Aid Highway Act later that year, the first legislation to make federal highway aid contingent on metropolitan transportation planning. This article traces the roots of the 1962 planning mandate through the development of research and techniques in the emerging field of transportation planning to craft a history of methods in travel demand forecasting or what the 1962 act referred to as the three C's of metropolitan transportation planning: a mandate for continuing, comprehensive, and coordinated planning efforts. Tracing this history sheds new light on the urban stakes of Interstate highway legislation in the 1950s and 1960s, as well as the role of cities in advocating for Interstate highway funding. The National Committee on Urban Transportation was an important catalyst of both methods in transportation planning and highway legislation.
Effects of Land Use Patterns on Tour Type Choice
Authors: Silva João de Abreu e , Sottile Eleonora , Cherchi Elisabetta
Published: February 2015

The relationships between travel behavior and land use patterns have been the object of intensive research in the past two decades. Because of their immediate policy implications, mode choice and vehicle miles traveled have been the main focus of attention. Other relevant dimensions, such as trip chaining, tour type choice, and number of tours, have received less attention. This paper contributes to research dealing with the role of land use patterns in tour type choice. A tour type choice is modeled with a hybrid choice model that allows simulating the effect of the latent propensity to travel in the discrete choice among types of tours. This model is applied to a travel diary of workers collected in the Lisbon, Portugal, metropolitan area in 2009. Various model specifications were built and tested the inclusion of purportedly built land use factors, which have the advantage of better capturing the multidimensionality of the urban environment or land use variables, or a combination of these. The results show significant effects on tour type choice related to land use patterns. Land use patterns influence not only the utility functions but also the propensity to travel. Workers who reside in central, mixed, and traditional urban spaces tend to have a higher propensity to travel. Workers who live in more diverse areas have a higher probability of engaging in more complex work-related tours. Working in suburban areas reduces the probability of engaging in more complex tours.
Effects of Rail Transit on Residential Property Values
Authors: Pan Qisheng , Pan Haixiao , Zhang Ming , Zhong Baohua
Published: February 2015

The impacts of a rail transit system on residential property values have been examined for many metropolitan areas in the United States, China, and other countries, yet there have been few comparison studies between countries. Studies have reported both the positive effects of rail transit resulting from improved accessibility as well as the nuisance effects from noise, pollution, crime, and unsightliness. The net effects of a rail transit system could be mixed, and there has been no agreement on which would dominate. This study used METRORail in Houston, Texas, and the Metro in Shanghai, China, as empirical cases and compared their effects on nearby residential property values. A hedonic price model with ordinary linear regression was used in the case study of Shanghai's rail transit lines. The Houston case study applied ordinary linear regression and multilevel regression techniques to examine the hierarchical structures of spatial data explicitly. The modeling results from both cases suggest that the overall effects of rail transit lines on residential property values are significantly positive. Notable variations of rail transit effects were also observed at various distance ranges and time spans.
Effects of Urban Fabric Changes on Real Estate Property Tax Revenue
Authors: Blanc Bryan P. , Gangi Michael , Atkinson-Palombo Carol , McCahill Christopher , Garrick Norman W.
Published: February 2015

Parking serves as the terminal facility for automobile-oriented transportation systems, but the impacts of its provision are often left unstudied. Providing too much parking in cities can undermine long-term transportation and development goals by creating a sparse or fragmented built environment. This study examined the changes in parking supplies, development characteristics, and travel mode shares in the past 60 years in six medium-sized cities. In three of these cities, parking supply increased significantly during the study period; in the other three cities parking supply increased only slightly. The main objective of this paper is to illustrate how these changes in parking supplies have affected the tax revenues in each city. An analysis based on geographic information systems was used to calculate the tax revenue of all properties in the study area of each city. Tax revenues generated from parking were quantified and were compared with tax revenues from nonparking uses on a proportional basis. Across the six cities, land occupied by surface parking contributed between 5% and 17% of the tax revenue that land occupied by taxable nonparking uses contributed. The analysis characterized an important concession involved in devoting large areas of land in the center of a city to surface parking.
From Car-Dependent Neighborhoods to Walkers’ Paradise
Authors: Li Wei , Joh Kenneth , Lee Chanam , Kim Jun-Hyun , Park Han , Woo Ayoung
Published: February 2015

Movement toward compact and walkable communities and low-carbon travel has gained momentum through various policy initiatives. However, residents’ willingness to pay for neighborhood walkability is still unknown. This study addresses that knowledge gap by quantifying walkability premiums based on 3,899 condominium sale transactions from 2010 to 2012 in Austin, Texas. Two measures of walkability were compared: Walk Score and Street Smart Walk Score. A spatial hedonic modeling approach improved estimation accuracy by controlling for spatial autocorrelation effects. The premium for walkability was found to be influenced by the pedestrian collision rate, street connectivity, length of sidewalks, speed limit, and various sociodemographic factors. A positive walkability premium was identified for 57% of sampled condominiums, most of which were located in neighborhoods that were at least somewhat walkable. The results could be used to identify investment priorities for creating walkable neighborhoods.
Megaregion Planning
Authors: Ross Catherine L. , Hylton Peter J. , Lee David Jung-Hwi
Published: February 2015

This paper assesses the state of practice in megaregion-scale transportation planning according to a survey of metropolitan planning organizations (MPOs) and state departments of transportation (DOTs) conducted by researchers at the Center for Quality Growth and Regional Development at the Georgia Institute of Technology in 2012. The survey was distributed to all MPOs and DOTs. Results cover a broad range of topics, including the state of practice, governance structures, planning approaches, general obstacles to megaregion planning and decision making, and finance. Megaregion-scale projects and cross-jurisdiction initiatives, whether contained within previously identified megaregions or extended beyond these geographic designations, received similar ratings of effectiveness. The Cascadia megaregion reported the highest percentage of organizations with cross-jurisdiction initiatives; the Midwest reported the highest absolute number. Planning and decision making within the megaregion were characterized by numerous actors interacting through largely informal or ad hoc processes with contested leadership. That partner roles were unclear likely increased uncertainty and transaction costs. Responses indicated that inadequate funding was one of the largest obstacles to megaregion planning. Funding was stagnant for DOTs and especially for MPOs. Practitioners did not appear to be optimistic about innovative funding methods that would fill gaps in megaregion transportation planning. Finally, governance networks were densest within states, but large MPOs, DOTs, and federal agencies may play a bridging role among states. Future research may focus on decreasing transaction costs, overcoming funding obstacles, and promoting dense interstate governance networks.