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It was determined in the mid- 1990s that Highway 95 in southern Nevada had experienced a tremendous increase in traffic and increased safety hazards for motorists due to growth in population and commerce in the Southwest. Federal, state, and local governments worked to find a solution to the impacts of increased traffic and have chosen a number of alternatives related to highway expansion. This is an American Indian ethnographic study for the Big Springs Highway 95 Corridor Project. The study area included the Big Spring Complex and associated American Indian sites potentially impacted by the westward expansion of U.S. 95 north of its junction with U.S. 15. The study does not include an analysis of U.S. 95 impacts to the east of the Big Springs complex towards what is known as Lorenzi Park. This report is based on interviews with American Indian representatives from six Southern Paiute tribes and the Las Vegas Indian Center. Each tribe and organization chose to send one or more tribal members to evaluate the potential impacts to American Indian cultural resources that would occur if Highway 95 were to be expanded to incorporate a portion of the current Big Spring location. This report provides the Southern Paiute evaluations of the proposed expansion.

Highway Authorities in the United Kingdom have jurisdiction to control, maintain and improve the local highway network, and the Road Traffic Act 1988 places a duty on such authorities to take preventative measures to reduce road casualties. As such, engineers working for the Highway Authority are on the ‘front-line,’ and are required to deal directly with lay concerns relating to road safety. This study investigates the nature and characteristics of how local road safety issues are raised and how engineers respond to such issues in a local authority setting. A grounded theory methodology was applied in the collection and analysis of this data, and in the generation of subsequent emergent themes. Datasets were established containing textual data from correspondence between the lay public and the authority, and from local press reporting. This was augmented by 47 semi-structured interviews with engineers. The analysis demonstrates that road safety issues and their construction, form a distinct genre. There are certain characteristic structural elements and argumentative approaches, which are oft repeated, in lay formulations of road safety. Road safety issues are played out in a contested field, although engineers may have, in theory, the ‘expertise’ that grants them authority to assess, diagnose and implement mitigation measures; in practice they have little autonomy or control. Regulatory restrictions, political interference, resource impoverishment and a volatile public, severely limit engineers’ independence and discretion. In dealing with the exigencies and pressures of day-to-day front-line public service, engineers deploy certain strategies for ‘managing’ the public. These pragmatic strategies are examined in order to establish how engineers can best effect practical action, in the face of competing and often conflicting demands. In examining the rhetorical organisation of lay argumentative strategies, a ‘popular epidemiology’ of road safety is recreated. This term, borrowed from Brown (1992), encapsulates a folk philosophy with respect to accident causation and the measures that are considered necessary or appropriate to ameliorate/eliminate identified issues. It is suggested that in vivo formulations of road safety issues, such as the ‘accident waiting to happen’ are founded on vague premises, and constitute a category mistake. Projections from phenomenally troubling, yet largely unsubstantiable events, to those with profound material consequences, are neither necessary nor certain. In making decisions on substantial capital investments, engineers, by necessity, are required to assess competing sites on a more epistemically secure metric, namely the police road casualty record.

The purpose of this research was to develop a simplified analytical procedure for determining the optimal timing for upgrading low-volume roads in developing countries. Most roadway upgradings from gravel to surface treated and to asphaltic concrete are carried out when total transport cost on a road becomes high as a result of high traffic and the consequent rapid deterioration of the roadway. Adequate timing of upgrading strategies ensures effective use of resources and lower total transport cost. This study examined existing systems, models, and approaches for estimating total transport cost components. An analytical procedure was then developed using a decision-tree concept to delineate all possible upgrading strategies within a plan period. The decision-tree concept depicts all the possible upgrading strategies within a plan period with decisions on roadway upgrading made at certain decision intervals. The total transport cost of the upgrading strategies is evaluated to establish the optimal strategies and traffic warrants for improving a roadway surface. A computer program PVMNT was written to facilitate the computation of the total transport cost. A case study was presented to demonstrate the application of the analytical procedure. The case study revealed interesting results on the changes of optimal upgrading strategies with changes in base traffic volume and growth rate. However, general conclusions could not be drawn based on the results of the case study. These results, as well as the analytical procedure, should be of interest to engineers responsible for providing low-volume roads in developing countries.

Road safety and traffic congestion are two of the critical issues facing the transportation profession today. As a means to promote safety and efficiency at United States intersections modern roundabouts are becoming more and more common. Over the last ten years, roundabouts implementation methodologies have been developed using data collected at U.S. roundabouts. These methodologies were first published in National Cooperative Highway Report 572: Roundabouts in the United States and more recently in the second edition of the national roundabout guidelines. This work attempts to validate the use of these methodologies for roundabouts in the state of Texas and also enhance guidelines for evaluating roundabout operations by exploring the effects of exiting flow, origin-destination patterns, and mean speed on roundabout entry-lane capacity. Capacity results from VISSIM are compared to the Highway Capacity Manual entry-lane capacity curve and results from SIDRA. / text

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Highway/railroad grade crossings present a danger to vehicular traffic. According to the USDOT Bureau of Transportation Statistics, in 2009, there were 1,887 crashes at highway/rail crossings resulting in 248 fatalities (FRA, 2009). The installation of presignals at grade crossings decreases crashes and fatalities at highway/rail crossings. There are no Federal standards that provide guidance for the installation of presignals. Therefore, current practices do not conform to any set of consistent nationwide standards except for guidelines specified in the MUTCD. These guidelines state that a presignal should be considered where the at-grade highway/rail crossing is located within 50 feet of a signalized intersection. The MUTCD also gives the option of installing a presignal at a distance greater than 50 feet, if an engineering study determines a need; however, no specific guidelines are provided for such studies.This work uses a case study to determine which measures are needed to warrant a presignal and examines if the distance criterion of 50 feet between signalized intersections and highway/rail crossings is adequate. It also explores the need for consistent national standards to provide guidance to practitioners in determining the needs for the installation of such signals.The study finds that distance criterion should not be used as the sole indicator for the installation of a presignal and therefore, engineering studies must be performed in all cases to determine presignal needs. Furthermore, the work concluded that the MUTCD must be modified to provide standards and guidelines that can be used nationwide for systematic quantitative assessment in determining when presignals are warranted near railroad crossings. This study proposes that presignals be installed based on warrants that consist of crash data, queue distance and no gates at the crossing. The proposed modifications include describing presignal types, defining their purpose, developing presignal warrants, and creating guidelines that can be used by practitioners.The changes and revisions recommended by this research work include queue length analysis, signal phasing and timing modifications, and existing intersection infrastructure needs. The resulting warrants and guidelines for presignal installation can be used nationally to provide uniform guidance and recommendations in performing presignal studies.

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The transportation infrastructure systems in the United States were built between the 50's and 80's, with 20 years design life. As most of them already exceeded their original life expectancy, State Transportation Agencies (STAs) are now under increased pressure to rebuild deteriorated transportation networks. Over the recent years, state transportation agencies (STAs) have taken into consideration various project delivery approaches apart from conventional project delivery approach to expedite project delivery. Since the introduction of these new alternative delivery approaches, not many substantial studies were conducted that evaluated the performance of these new alternatives. The absence of systematic studies about the effectiveness of these strategies and lack of appropriate analytical tools to evaluate them inhibits the STAs from budgeting precisely and accurately these strategies when they are deliberated for being put into practice. This study tries to address these limitations by evaluating the effectiveness of these strategies. The major objectives of this research were: 1) to evaluate the impact of contracting strategies on dealing with change orders 2) to evaluate the performance of different contracting strategies under varied work type for the state of Florida . For this research the study was conducted to quantify the changes to project duration and cost caused by change orders in the project under different contracting strategies and type of work. This was done through evaluating 2844 completed transportation infrastructure projects, completed between 2002 and 2011 in the state of Florida. These projects comprised of both the conventional projects and innovative alternative projects. The data was then statistically analyzed for evaluating the performance of these contracting strategies. The research concluded that alternative contracting strategies perform much better than conventional contracting in controlling project schedule but are found not to be as effective in controlling the project cost growth. The study also established that project size and work type affect the effectiveness of the contracting strategies. The study indicates that A+B is the worst performing contracting strategy among all the strategies evaluated. The results of this study will help the STAs to make better informed decision regarding selection of contracting strategy for project delivery.

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