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  • - Capitalizing on International Experience
    af Federal Highway Administration
    207,95 kr.

    Comprehensive highway public-private partnership (PPP) programs are relatively new to the United States and not widely used. Limited highway funds, unmet needs for new highway capacity, interest from private investors, and other factors have led to substantial discussion of PPP projects and programs at the State and Federal levels and implementation of projects in a few leading States. In contrast, some countries have extensive and, in some cases, long-term experience with infrastructure PPPs, particularly highways. This presents a unique opportunity to capitalize on the knowledge and experience gained in the international community, where tested policies and practices are in place. A desk study was completed to identify the countries with the most potential to provide relevant and current information on PPPs. Subsequently, a team of nine professional representing government, private industry, and academe visited Australia, Portugal, Spain, and the United Kingdom in June 2008 to collect and evaluate information about PPP programs and projects for highway infrastructure. The team met with representatives of the public and private sectors involved in PPP arrangements. The Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) jointly sponsored this scan through the National Cooperative Highway Research Program (NCHRP).

  • af Federal Highway Administration
    217,95 kr.

    In 2004, a team of representatives from the Federal Highway Administration, State highway agencies, industry, and academia visited Canada, Finland, Germany, the Netherlands, Scotland, and the United Kingdom. The purpose of this International Technology Scanning Program study was to identify practices that might be evaluated and applied in the United States to improve construction management. One significant scan finding was that the countries visited had an advanced awareness of risk assessment and allocation techniques that are just now evolving in U.S. highway agencies. This instructional report was developed as part of the scan team's implementation plan to raise awareness of risk management techniques and begin the process of incorporating risk management elements into the institutional structures of highway agencies. The report is designed to be used in conjunction with workshops on implementing risk management.

  • - A Guide to Using Performance Goals and Measures to Improve Project Delivery
    af Federal Highway Administration
    252,95 kr.

    Much of America's transportation infrastructure is reaching the end of its design life and needs to be reconstructed. At the same time, traffic levels and the resulting congestion levels continue to increase steadily. These two factors combined pose a significant challenge to State Departments of Transportation (DOTs) and the Federal Highway Administration (FHWA). To address this challenge, FHWA has been working with State DOTs and industry to develop a "toolbox" of potential solutions. One tool in this toolbox is performance contracting. Performance contracting is an approach where a private contractor is responsible for achieving a defined set of goals, and where performance goals are specified instead of methods. Using a performance contracting approach will allow owner agencies to define and communicate to construction contractors specifically what they and FHWA want to achieve in their construction projects. The construction contractors on performance contracts should share the risks and rewards as a project partner, and defined performance goals and measurement methodologies will provide a basis for applying incentives and disincentives. However, it must be stressed that for a performance contract to be successful, the contractor must be provided with flexibility on how to perform the work and the performance goals must be under the control/influence of the contractor. FHWA has been working over the past 15 years on evaluating alternative contracting procedures under the Special Experimental Projects No. 14 (SEP-14) program. These procedures, which include performance contracting, incentives/disincentives, and Best Value awards, have resulted in time/cost savings and improved contract management. FHWA anticipates that the use of these procedures will expand greatly in the future as a means of addressing current challenges. The purpose of this Guide is to provide States with processes and materials that they can use to accelerate the development of a performance contract solicitation package for construction contracts.

  • af Federal Highway Administration
    207,95 kr.

    This primer has been developed to assist agencies in establishing and monitoring a useful set of work zone safety and mobility performance measures. Work zone performance measures are metrics that help to quantify how work zones impact travelers, residents, businesses and workers. Work zone performance measures help agencies improve their understanding of how their decisions during planning, design, and construction affect work zone safety and mobility, and thus can help improve how they make decisions for future work zones. The primer describes possible work zone performance measures, and provides guidance to help agencies select and implement measures that make sense for their own work zone programs. The primer outlines the methods and technologies that are available to gather data to monitor the various possible measures and procedures for calculating specific performance measures from different types of work zone traffic monitoring data. The primer also discusses the use of measures across multiple projects to assess an agency's overall efforts and outcomes against its policies and goals.

  • af Federal Highway Administration
    227,95 kr.

    Multiple governmental jurisdictions have responsibilities for the transportation systems that provide access to or within Federal lands. Transportation networks are seamless only when these networks are managed holistically. It is critical that Federal agency transportation planning efforts be integrated with those of the States, other Federal agencies, Tribal governments, Metropolitan Planning Organizations (MPOs), counties, and communities to improve the effectiveness of the entire system. Local communities-and the Federal lands that border them-are intricately linked. Federal lands adjacent to communities contribute significantly to the economy, cultural identity, and quality of life in these communities. They provide scenic beauty and recreational opportunities and help nourish ecological values, benefiting local communities and nearby metropolitan areas. As members of the greater community, Federal land management agency transportation planners and other managers need to work with area leaders to create transportation, land use, and economic development strategies that preserve natural resources while supporting local economic and other community objectives. Better transportation links are emerging between State and local transportation systems including transit systems and Federal land transportation systems to help people access Federal land. As the connection between these systems becomes more seamless, this coordinated transportation network stimulates new Federal land uses and activities for recreation, allows for more effective land management, and enhances rural transportation infrastructure for surrounding private land. However, this increased use creates challenges for maintaining natural resources such as wildlife, fish, plants, cultural resources, water quality, stream function, and environmental quality overall. The guidebook is designed to assist Federal land managers, staff, and partners in developing relationships and in maximizing participation in Federal Highway Administration (FHWA) and Federal Transit Administration (FTA) surface transportation programs. With the technical assistance available through the FHWA and the FTA, the agencies can help further regional and local community goals and better fulfill their mission including resource protection and environmental quality. Seamless transportation systems and Federal land management agencies' commitment to building better relationships with States and other partners helps agencies achieve their mission and provide effective land stewardship and public service. The FHWA and FTA funding is very flexible and can be used for many activities beyond just constructing roads including enhancing roadside areas, providing traveler services, constructing trails, and improving environmental conditions alongside roads and trails. Most of the funding available through Federal surface transportation programs cannot be accessed directly by the Federal land management agencies (FLMAs). To benefit from most of these FHWA and FTA funding programs, the Federal agencies must partner with the State or local governments. Agencies must participate in the State's and/or region's transportation planning process to ensure that projects that are important to the agencies are included in the State's project priority list known as the statewide transportation improvement program or STIP. In a metropolitan area, projects must be included in a similar list called the transportation improvement program or TIP, which is ultimately incorporated into the STIP, either directly or by reference. This guidebook outlines the transportation planning process and serves as a primer on: Which activities are eligible for funding; Where to find funding; Actions required for Federal land managers to access and benefit from these funds and programs; Which agencies to partner with; How to integrate Federal land management objectives with State and local objectives.

  • af Federal Highway Administration
    252,95 kr.

    Currently, a well-defined and validated set of metrics to use in monitoring work zone performance do not exist. This pilot test was conducted to assist state DOTs in identifying what work zone performance measures can and should be targeted, what data they will need to collect to compute those measures, and what methods exist to obtain that data. Work zone activity and traffic data from five work zone projects were gathered and analyzed. Multiple data sources and collection methods were examined and utilized to the extent available at each project. These sources were field crew personnel manually documenting queue presence, length, and duration; traffic surveillance data from a transportation management center or from portable work zone ITS; and third-party probe vehicle data (in this test, large truck speed data obtained via the FHWA Office of Freight Management). The results of the pilot test indicate that manual documentation of queuing by field personnel, and the use of permanent or portable traffic sensor data can be used effectively to measure work zone impacts, given that information as to the time and location of work activities is known. Probe vehicle data is also believed to be a viable source of data, but sample size issues did limit is applicability in this pilot test. Average and maximum queue lengths and duration, duration of queues exceeding pre-determined thresholds, vehicle exposure to queues, and vehicle delays when queues are present were among the several performance measures tested and demonstrated as viable indicators of work zone mobility impacts. A number of lessons learned through this pilot test effort are also included in the report.

  • af Federal Highway Administration
    207,95 kr.

    In 2004, the Federal Highway Administration published updated rules governing work zone safety and mobility; all highway construction and maintenance projects using federal-aid highway funds are required to develop transportation management plans (TMP) focusing on safety and the reduction of traffic mobility impacts through coordination. The project TMP should consist of a collection of administrative, procedural, and operational strategies for managing and mitigating the impacts of work zones. It is important for planners, operations personnel, and incident responders to understand why the transportation operation elements are vital in the process of developing the TMP. This document addresses the special needs and concerns when managing traffic incidents within a work zone and focuses on incident management as a strategy to be considered in the transportation operations component of the TMP. A description of techniques and strategies that can be used to handle incidents in work zones is presented. Some trend-setting approaches used on high-profile construction projects are also showcased as examples of good incident response planning incorporated at the design level. The contractor's role in dealing with incidents within the work zone is addressed as well as the description of processes, procedures, and practices related to the detection, response, and clearance of incidents. The importance of including incident management procedures as an element of the transportation operations component of these plans is emphasized. The goals, objectives, and reasons for incident management as well as the issues and concerns that work zone planners, incident responders, and traffic operators need to consider in the planning phases of a work zone project are presented. Common work zone incident management strategies are described.

  • - Third Edition
    af Federal Highway Administration
    307,95 kr.

    The purpose of this publication is to provide design information for analyzing and mitigating energy dissipation problems at culvert outlets and in open channels. It provides general information on the overall design process, erosion hazards, and culvert outlet velocity and velocity modification. These provide a background and framework for anticipating dissipation problems. In addition to describing the overall design process, design examples to compare selected energy dissipators are provided. Also provided are assessment tools for considering flow transitions, scour, and hydraulic jumps.

  • - A Comprehensive Model for Estimating Employment Generation from Federal-Aid Highway Projects
    af Federal Highway Administration
    162,95 kr.

    JOBMOD2 is a model that makes quantitative estimates of the total employment income and jobs supported by federally funded highway improvement projects. This includes not only the direct employment of construction workers, but also all those workers who are required to produce inputs to the construction project. It also goes a step further by estimating the number of jobs that are supported by the growth in consumer expenditure that arises due to all the employment income from those jobs supported by the project. Thus, it provides a very broad definition of the total employment impact of expenditures on highway improvements. The term "highway improvement" can cover a broad range of things, including construction of new highways; reconstruction of old highways; construction, reconstruction or major repair of bridges; improvement of signal systems and traffic flow systems for the purpose of congestion reduction or safety enhancement; and highway alterations for environmental purposes such as the installation of sound barriers. Furthermore, a substantial proportion of highway funds may be spent not on construction per se, but on engineering design services. Since these different types of activities will produce different employment impacts, JOBMOD2 makes it possible for the user to specify the highway improvement type. Highway construction is a relatively labor intensive activity that directly employs a variety of people including laborers, equipment operators, vehicle drivers, engineers, managers and supervisors. Thus, assuming that there is slack labor supply, each construction project creates a number of new jobs directly. It also creates a number of jobs indirectly through its incremental demand for inputs such as steel, concrete, aggregates, lighting equipment etc. Labor is required to produce all of these inputs and to produce inputs to the production of these inputs.

  • af Federal Highway Administration
    197,95 kr.

    Pressure flow (also known as vertical contraction) scour occurs when a bridge deck is insufficiently high such that the bridge superstructure becomes a barrier to the flow, causing the flow to vertically contract as it passes under the deck. A bridge deck is considered partially submerged when the lowest structural element of the bridge is in contact with the flowing water but the water is not sufficiently high to overtop the bridge deck. It is considered fully submerged when a portion of the flow overtops the bridge deck. Pressure flow generally only occurs in extreme flood events, but these types of events are relevant for estimation of scour. When flow is sufficiently high so that it begins to approach the elevation of the bridge deck, some of the flow may be diverted laterally to the bridge approaches. Since the bridge approaches are often lower than the bridge deck, this diversion may reduce the scour potential under the bridge. Designers must evaluate the effects of scour under the bridge as well as potential damage caused by flow diversion. An experimentally and numerically calibrated scour model was developed in this study to calculate the maximum clear water scour depth in non-cohesive bed materials under different deck inundation conditions. The theoretical formulation of the model is based on the conservation of mass of the water passing underneath the bridge deck. Particle image velocimetry (PIV) measurements and computational fluid dynamics (CFD) simulations were used to validate assumptions used in the derivation and verify calibration of parameters included in the scour model. As one of the important parameters in the pressure flow scour model, the separation zone thickness in the bridge opening was formulated analytically, calibrated experimentally, and verified by PIV and CFD analyses. The maximum scour depth was calculated by identifying the total bridge opening that resulted in the average velocity in the opening that is equal to the critical velocity of the bed material. This report summarizes a literature review on pressure scour and describes the physical and theoretical foundation for the model formulation. The newly collected flume data as well as PIV and CFD analyses are summarized. The model formulation is refined, tested, and compared to other approaches used to estimate pressure scour. Recommendations for model application are also provided.

  • - Fourth Edition
    af Federal Highway Administration
    317,95 kr.

    Approximately 500,000 bridges in the National Bridge Inventory (NBI) are built over streams. A large proportion of these bridges span alluvial streams that are continually adjusting their beds and banks. Many, especially those on more active streams, will experience problems with aggradation, degradation, bank erosion, and lateral channel shift during their useful life. The purpose of this document is to provide guidelines for identifying stream instability problems at highway stream crossings. Techniques for stream channel classification and reconnaissance, as well as rapid assessment methods for channel instability are summarized. Qualitative and quantitative geomorphic and engineering techniques useful in stream channel stability analysis are presented. This publication is an update of the third edition published in 2001. The HEC-20 manual covers geomorphic and hydraulic factors that affect stream stability and provides a step-by-step analysis procedure for evaluation of stream stability problems. Stream channel classification, stream reconnaissance techniques, and rapid assessment methods for channel stability are covered in detail. Quantitative techniques for channel stability analysis, including degradation analysis, are provided, and channel restoration concepts are introduced. Significant new material in this edition includes chapters on sediment transport concepts and channel stability in gravel bed streams, as well as expanded coverage of channel restoration concepts.

  • af Federal Highway Administration
    272,95 kr.

    This Manual includes state-of-the-art information relative to materials, post-tensioning systems, construction practices and grouting of post-tensioning tendons for bridges. The Manual is targeted at Federal, State and local transportation department and private company personnel that may be involved in the design, inspection, construction or maintenance of bridges that contain post-tensioning tendons. This Manual will serve as a reference and guide to designers, inspectors and construction personnel for post-tensioning materials, installation and grouting of bridge tendons. The document is part of the Federal Highway Administration's national technology deployment program and may serve as a training manual.

  • - Experience, Selection and Design Guidance - Third Edition: Volume 2
    af Federal Highway Administration
    342,95 kr.

    This publication identifies and provides design guidelines for bridge scour and stream instability countermeasures that have been implemented by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selection, and design guidance are consolidated from other FHWA publications in this document to support a comprehensive analysis of scour and stream instability problems and provide a range of solutions to those problems. Selected innovative countermeasure concepts and guidance derived from practice outside the United States are introduced. Management strategies and guidance for developing a Plan of Action for scour critical bridges are outlined, and guidance is provided for scour monitoring using portable and fixed instrumentation. The results of recently completed National Cooperative Highway Research Program (NCHRP) projects are incorporated in the design guidance, including: countermeasures to protect bridge piers and abutments from scour; riprap design criteria, specifications, and quality control; and environmentally sensitive channel and bank protection measures. This additional material required expanding HEC-23 to two volumes. Volume 1 now contains a complete chapter on riprap design, specifications, and quality control as well as an expanded chapter on biotechnical countermeasures. The guidance on scour monitoring instrumentation has been updated and now includes additional installation case studies. Volume 2 contains 19 detailed design guidelines grouped into six categories, including countermeasures for: (1) stream instability (2) streambank and roadway embankment protection, (3) bridge pier protection, (4) abutment protection, (5) filter design, and (6) special applications.

  • - Third Edition
    af Federal Highway Administration
    272,95 kr.

    Debris accumulation at culvert and bridge structures openings is a widespread problem. The accumulation of debris at inlets of highway culverts and bridge structures is a frequent cause of unsatisfactory performance and malfunction. This accumulation may result in erosion at culvert entrances, overtopping and failure of roadway embankments and damage to adjacent properties, increased local scour at piers and/or abutments, and the formation of pressure flow scour. Consideration of debris accumulations and the need for debris-control structures should be an essential part of the design of all drainage structures. Structural and non-structural measures have been used effectively to prevent or reduce the size of debris accumulations at bridges and culverts. Structural measures can include features that: (a) intercept debris at or upstream of a structure inlet; (b) deflect debris near the inlet; or (c) orient the debris to facilitate passage of the debris through the structure. Non-structural measures include management of the upstream watershed and maintenance. This publication provides measures for both culvert and bridge structures. The measures available for culverts are based on the information included in earlier editions of this manual. Selection of a certain debris countermeasure depends upon the size, quantity, and type of debris, the potential hazard to life and property, the costs involved, and the maintenance proposed.

  • af Federal Highway Administration
    207,95 kr.

    Bridges are a vital component of the transportation network. Evaluating their stability and structural response after a flood event is critical to highway safety. Bridge studies are usually designed with an assumption of an open channel flow condition, but the flow regime can switch to pressure flow when the downstream edge of a bridge deck is partially or totally submerged during a large flood. Figure 1 shows a bridge undergoing partially submerged flow in Salt Creek, NE, in June 2008. Figure 2 shows a totally submerged flow in Cedar River, IA, in June 2008, which interrupted traffic on I-80. Unlike open channel flows, these pressure flows create a severe scourability potential because scouring the channel bed is one of the only ways to dissipate the energy when passing a given discharge in pressurized flow. Although most bridge scour events are due to live bed scour, a maximum scour depth often results from clear water flows with a critical approach velocity for bedload motion. For bridge safety, this report emphasizes the equilibrium maximum scour of pressure flows in extreme clear water conditions. The objectives of the study were to collect a detailed high-quality dataset of pressure flow scour at a model bridge and to develop an analytical solution for pressure flow scour based on mass and energy conservation laws. To these ends, existing results in the literature were reviewed, and knowledge gaps were identified. Next, a series of flume experiments were conducted to examine the existing methods and test new hypotheses on bridge pressure flow scour. After, bridge flows were divided into three cases, and the mass and energy conservation laws were applied to each case, leading to hypotheses for pressure flow scour predictions. The hypotheses were tested with the flume data. In this report, an example procedure for calculating the maximum scour depth and scour profile is presented along with recommended research needs.

  • af Federal Highway Administration
    297,95 kr.

    This publication provides a comprehensive and practical guide for the design of stormwater pump station systems associated with transportation facilities. Guidance is provided for the planning and design of pump stations which collect, convey, and discharge stormwater flowing within and along the right-of-way of transportation systems. Methods and procedures are given for determining cumulative inflow, system storage needs, pump configuration and selection, discharge system size, and sump dimensions. Pump house features are identified and construction and maintenance considerations are addressed. Additionally, considerations for retrofitting existing storm water pump stations are presented.

  • - Fifth Edition
    af Federal Highway Administration
    362,95 kr.

    The most common cause of bridge failures is from floods scouring bed material from around bridge foundations. Scour is the engineering term for the erosion caused by water of the soil surrounding a bridge foundation (piers and abutments). The purpose of this document is to provide guidelines for the following: 1. Designing new and replacement bridges to resist scour, 2. Evaluating existing bridges for vulnerability to scour, 3. Inspecting bridges for scour, 4. Improving the state-of-practice of estimating scour at bridges. This document is the fifth edition of HEC-18. It presents the state of knowledge and practice for the design, evaluation and inspection of bridges for scour. There are two companion documents, HEC-20 entitled "Stream Stability at Highway Structures," and HEC-23 entitled "Bridge Scour and Stream Instability Countermeasures." These three documents contain updated material from previous editions and continued research by NCHRP, FHWA, State DOTs, and universities. This fifth edition of HEC-18 also contains revisions obtained from further scour-related developments and the use of the 2001 edition by the highway community. The major changes in the fifth edition of HEC-18 are: expanded discussion on the policy and regulatory basis for the FHWA Scour Program, including risk-based approaches for evaluations, developing Plans of Action (POAs) for scour critical bridges, and expanded discussion on countermeasure design philosophy (new vs. existing bridges). This fifth edition includes: a new section on contraction scour in cohesive materials, an updated abutment scour section, alternative abutment design approaches, alternative procedures for estimating pier scour, and new guidance on pier scour with debris loading. There is a new chapter on soils, rock and geotechnical considerations related to scour. Additional changes include: a new approach for pier scour in coarse material, new sections on pier scour in cohesive materials and pier scour in erodible rock, revised guidance for vertical contraction scour (pressure flow) conditions, guidance for predicting scour at bottomless culverts, deletion of the "General Scour" term, and revised discussion on scour at tidal bridges to reflect material now covered in HEC-25 (2nd Edition).

  • af Federal Highway Administration
    197,95 kr.

    This document is meant to help transportation agencies plan and implement effective public information and outreach campaigns for work zones. The focus of this document is not on project selection and design, but on the travel impacts of a work zone - such as lane closings, new traffic patterns, and traffic delay - and available travel alternatives (e.g., different routes and travel modes). This document provides information and strategies for developing public information and outreach campaigns for specific work zones, rather than general work zone education and safety campaigns. It is primarily designed for personnel in transportation agencies responsible for planning and operating highway work zones and those responsible for public relations and public information. It will also be of interest to transportation policy makers, work zone contractors, consultants, public relations firms, and emergency responders. This document also provides support to agencies in their efforts to implement the recently updated work zone regulations. In September 2004, the Federal Highway Administration (FHWA) published updates to the work zone regulations at 23 CFR 630 Subpart J. The updated rule addresses the use of public information and outreach as a work zone management tool. The updated rule is referred to as the Work Zone Safety and Mobility Rule (Rule) and applies to all State and local governments that receive Federal-aid highway funding. Transportation agencies are required to comply with the provisions of the Rule by October 12, 2007. The changes made to the regulations broaden the former rule to better address the work zone issues of today and the future. Growing congestion on many roads, and an increasing need to perform rehabilitation and reconstruction work on existing roads already carrying traffic, are some of the issues that have lead to additional, more complex challenges to maintaining work zone safety and mobility. To help address these issues, the Rule provides a decision-making framework that facilitates comprehensive consideration of the broader safety and mobility impacts of work zones across project development stages, and the adoption of additional strategies that help manage these impacts during project implementation. The Rule requires agencies to develop an agency-level work zone safety and mobility policy to support systematic consideration and management of work zone impacts across all stages of project development. Based on the policy, agencies will develop processes and procedures to support implementation of the policy. The third primary element of the Rule calls for the development of project-level procedures to address the work zone impacts of individual projects. This includes requirements for identifying significant projects and developing and implementing transportation management plans (TMPs) for all projects. For significant projects, the TMP must include public information and outreach strategies to inform those affected by the project of expected work zone impacts and changing conditions. This document is the second of four guidance documents on the Rule and contains guidance, as well as many examples of work zone public information and outreach campaigns used by transportation agencies.

  • af Federal Highway Administration
    252,95 kr.

    Current Federal Regulations (23 CFR 630 Subpart J) encourage States to collect and analyze both safety and mobility data to support the initiation and enhancement of agency-level processes and procedures addressing work zone impacts. The purpose of this guidance document is to provide practitioners with the skills to identify current data sources (both existing data and data collected specifically for the work zone) for use in work zone performance measurement, as well as potential data sources that could be useful to work zone performance measurement in the near future. This document is also intended to assist practitioners in determining how to select and compute useful work zone performance measures, given the data sources available to them. For both current and potential data sources, guidance is presented on the viability of each source for work zone performance measurement, as well as on possibly leveraging opportunities to maximize the value of data collection and extraction efforts. In addition to information about data sources and opportunities, guidance is provided regarding work zone performance measures that the various data sources can support. Where appropriate, examples are provided as to how data assessment, collection, application, and interpretation can be accomplished. In this way, document users can obtain an overall perspective.

  • - 2004 Edition
    af Federal Highway Administration
    522,95 kr.

    Detailed drawings of the Standard Highway Signs prescribed or provided for in the Manual on Uniform Traffic Control Devices (MUTCD), 2003 Edition, have been prepared by the Office of Transportation Operations, Federal Highway Administration, U. S. Department of Transportation, for use by all traffic authorities, agencies, jurisdictions and persons involved with the fabrication, installation and maintenance of traffic signs on streets and highways in the United States. These drawings are presented in English units as an alternate to metric dimensional designs. They are provided to promote uniformity in design throughout the United States in accordance with Title 23, U.S. Code, Sections 109(b), 109(d) and 402 (a), and Highway Safety Program Standard 13, "Traffic Engineering Services". As stated in the MUTCD, "Uniformity in design includes shape, color, dimensions, legends and retroreflection. This manual shows typical signs approved for use on streets and highways. Detailed drawings of these and other approved signs are available to State and local highway and traffic authorities and similarly interested agencies. All symbols shall be unmistakably similar to those shown and where a word message is applicable, the wording shall be as herein provided unless alternative wording is optional. Most standard symbols are oriented facing left; however, this does not preclude the use of mirror images of these symbols where the reverse orientation might better convey a direction of movement to vehicle operators. Standardization of these designs does not preclude further improvements by minor changes in the proportion of the symbols, width of borders, or layout of word messages, but all shapes and colors shall be as indicated.

  • - Concepts and Applications
    af Federal Highway Administration
    307,95 kr.

    On-site construction activities can result in significant mobility and safety impacts to road users. The presence of work zone can also result in inconvenience to local business and community, noise and environmental impacts. Minimizing the adverse impacts of work zones has become a higher priority especially since the inception of the FHWA Rule on Work Zone Safety and Mobility (23 CFR 630 Subpart J). Work zone road user costs (WZ RUC) provide the economic basis for quantifying these adverse impacts which can then be used for effective decision-making to improve work zone mobility and safety. This report provides practitioners with information on WZ RUC analysis concepts and their applications using case studies drawn from real world projects. WZ RUC primarily refers to monetized components of mobility and safety impacts; increasingly, non-monetary and qualitative components, such as environmental, business, and societal impacts, are being utilized. In this report, each of the monetary components is explored and the computations of these components are illustrated using examples. It presents step-by-step procedures to derive unit costs for monetary components. It lists the cost sources for each cost component as well as the ways to update those using economic indices. It also explores input requirements and various tools available for use in WZ RUC analysis. This report presents the application of both monetary and qualitative components of WZ RUC in MOT alternative analysis using a decision analysis framework. Another key application of WZ RUC is in selecting appropriate project delivery/contracting strategies to minimize WZ RUCs and related impacts through early project completion. Approaches for determining an appropriate level of incentives and disincentives are also discussed. Three "real-world" case studies from the Highways for LIFE program are presented to demonstrate the applications of WZ RUCs in selecting the preferred Maintenance of Traffic (MOT) alternatives and project delivery/contracting strategies.

  • af Federal Highway Administration
    452,95 kr.

    These Standard Specifications for the Construction of Roads and Bridges on Federal Highway Projects are issued primarily for constructing roads and bridges on Federal Highway projects under the direct administration of the Federal Highway Administration. These specifications are cited as "FP-03 U.S. Customary Units" indicating "Federal Project" Standard Specifications issued in 2003 and converted to United States customary measure units. U.S customary units were previously referred to as English units and are the units of measurement customarily used in the U.S. today. When designated in a contract, the FP-03 becomes part of the contract and binding upon all parties to the contract. All construction contracts of the Federal Highway Administration are also governed by the following regulations: Federal Acquisition Regulation (FAR), Title 48, Code of Federal Regulations, Chapter 1; and Transportation Acquisition Regulation (TAR), Title 48, Code of Federal Regulations, Chapter 12. The FAR and TAR regulations are not included in the FP-03. A complete copy of the FAR is available from the Superintendent of Documents, Congressional Sales Office, U.S. Government Printing Office, Washington, DC 20402. U.S. customary measure units are used in the FP-03 U.S. Customary Units as authorized by the Waiver Request of DOT Metric Policy.

  • af Federal Highway Administration
    297,95 kr.

    This manual presents a stream simulation design procedure, methods and best practices for designing culverts to facilitate aquatic organism passage (AOP). Although this manual focuses on culverts, the design team should recognize that an appropriate structure for any given crossing may be a bridge. This manual is not intended to conflict with or replace accepted guidance and procedures adopted in particular locations. When specific water crossing design methods are required in the jurisdiction where the crossing is located, those methods should be applied. In addition, local and regional requirements may overlay additional steps on this design approach. Since fish have been the primary focus of AOP design efforts over the years, and much has been learned about fish specifically, many of the references to AOP in this manual derive directly from what is known about fish. However, the broader scope of AOP is the focus of the manual. Because of the variety of fish and other aquatic species in the U.S., the complex nature of fish behavior, and the variation in such behaviors and capabilities over the various life-stages, designing hydraulic structures with satisfactory aquatic organism passage (AOP) characteristics remains a challenging endeavor. Over the years, resource agencies and others have assembled a large amount of empirical data and field experience to guide the design of roadway structures, particularly culverts, for passage. Much of the resulting criteria are based upon the natural geomorphic characteristics of streams supporting the aquatic ecosystems of interest, and many of the procedures implementing those criteria seek to replicate the stream and floodplain characteristics and geometries within the roadway crossing structure. The "stream simulation" approach such as developed by the United States Forest Service (FSSWG, 2008) is one approach that is state of the art. Given the diverse behavior and capabilities of fish and other aquatic organisms, design procedures necessarily rely on surrogate parameters and indicators as measures for successful passage design. Many of the existing AOP design procedures rely on dimensional characteristics of the stream such as bankfull width. A critique of the use of dimensional stream characteristics is that they: 1) can be difficult to identify, 2) can be highly variable within a stream reach, 3) assume the stream is in dynamic equilibrium, and 4) have no known relationship to passage requirements. The procedure described in this manual uses streambed sediment behavior as its surrogate parameter. The hypothesis of using sediment behavior as a surrogate parameter is that aquatic organisms in the stream are exposed to similar forces and stresses experienced by the streambed material. The design goal is to provide a stream crossing that has an equivalent effect, over a range of stream flows, on the streambed material within the culvert compared with the streambed material upstream and downstream of the culvert. When this is achieved and the velocities and depths are comparable to those occurring in the stream, the conditions through the crossing should present no more of an obstacle to aquatic organisms than conditions in the adjacent natural channel. The primary goal of this document is to incorporate many of the current geomorphic-based design approaches for AOP while providing a procedure based on quantitative best practices. The stream simulation design procedure is intended to create conditions within the crossing similar to those conditions in the natural channel to provide for aquatic organism passage (AOP). This document seeks to identify, develop, and present a bed stability-based approach that accounts for the physical processes related to the natural hydraulic, stream stability, and sediment transport characteristics of a particular stream crossing as surrogate measures.

  • - Use of Technology and Data for Effective Work Zone Management
    af Federal Highway Administration
    217,95 kr.

    ITS is the use of a broad range of communications-based information and electronics technologies to enhance transportation. Work zone ITS is the use of ITS to enhance transportation and improve safety and mobility in and around work zones. A work zone ITS deployment can be focused around safety or mobility, but often supports both goals, and can also enhance productivity. The systems are portable and temporary in most cases, although some deployments may use either existing fixed infrastructure or become a permanent system. The purpose of this document is to provide guidance on implementing ITS in work zones to assist public agencies, design and construction firms, and industry, including developers, manufacturers, distributors, packagers, and providers of devices, systems, and programs. Work zone ITS is one possible operational strategy of many potential solutions that an agency can include in a transportation management plan (TMP). This document summarizes key steps for successfully implementing ITS in work zones, using a systematic approach to provide a technical solution that accomplishes a specific set of clearly defined objectives. The document illustrates how a systems engineering process should be applied to determine the feasibility and design of work zone ITS for a given application, regardless of its scale, by walking through the key phases, from project concept through operation. These steps include assessment of needs; concept development and feasibility; detailed system planning and design; procurement; system deployment; and system operation, maintenance, and evaluation.

  • af Federal Highway Administration
    297,95 kr.

    This manual has been developed to provide construction project personnel with information and guidance for field activities relating to materials. This manual complements the Standard specifications for Construction of Roads and Bridges on Federal Highway Projects (FP). When the guidelines or directions set forth in this manual conflict with an FLH contract, the contract shall govern. This manual is intended as general guidance. It sets forth procedures and best practices for testing and verifying materials on a contract. The application of this manual to any particular situation is to be guided by sound engineering principles. This manual does not create enforceable rights. However, a contract may adopt or incorporate by reference any portion of this manual and thereby establish that portion as binding on the parties. The manual is divided into five chapters and six divisions. Chapter 1 - Division 100: Acceptance and Verification Procedures and Material Project Requirements; Chapter 2 - Division 200: Earthwork Testing and Evaluation; Chapter 3 - Division 300: Aggregate Base, Subbase, Aggregate-Topsoil, and Base Stabilization; Chapter 4 - Division 400: Asphalt Pavements and Surface Treatments; Chapter 5 - Division 500: Concrete. Chapter 1 processes and procedures are generally applicable to the categories of materials addressed in Chapters 2 through 5. Chapters 2 through 5 set forth the processes needed to address the categories of materials specifically addressed in each particular chapter.

  • af Federal Highway Administration
    207,95 kr.

    People need walkable communities where sidewalks, trails, and street crossings are safe, accessible, and comfortable for people of all ability levels. Pedestrian-friendly communities have many benefits, including: Safer environments for walking and bicycling, which means you are less likely to be in a traffic collision or get injured; Better access to more places, providing more choices in how you can get to your destinations so you don't have to rely on having a car; More opportunities to be physically active, which can improve your health and overall quality of life; and Opportunities for everyone, which includes a walking environment that accommodates people with disabilities. It takes the commitment and involvement of many people to build and maintain places that are safe and friendly for walking. This guide is designed to be used by anyone looking for ways to improve the walkability of their neighborhood, whether they are just beginning to learn about pedestrian safety or are already part of an established community safety group. Residents can make a difference by raising awareness of pedestrian safety issues and pushing for change. This guide provides examples from other communities working to improve pedestrian safety. It includes information, ideas, and resources to help residents learn about issues that affect walking conditions; find ways to address or prevent these problems; and promote pedestrian safety. The Resource Sheets at the end of the guide contain fact sheets, worksheets, and sample materials - these materials can be adapted to meet the needs of your community, or distributed to others working to improve pedestrian safety. The guide provides a thorough introduction to pedestrian safety and includes many references to other resources and materials for those interested in more in-depth information.

  • - Findings from a Virtual Review
    af Federal Highway Administration
    197,95 kr.

    The Federal Highway Administration (FHWA) conducted an international review to study how international transportation agencies are addressing issues related to adapting highway infrastructure to the impacts of climate change. The review involved transportation agencies from Australia, Canada, Denmark, Korea, New Zealand, the Netherlands, Norway, and the United Kingdom. The review elicited information on adaptation issues associated with all aspects of the transportation project delivery process. This synthesis report highlights the state of the practice of how transportation agencies are addressing climate adaptation through the following: adaptation frameworks/strategies; climate change risk assessments; selecting adaptation measures and strategies; long range planning and land use; changes in design standards; maintenance and operations; asset management; and research. The information collected during the review and presented here is relevant to transportation planners, asset managers, design engineers, and policy-makers.

  • - Third Edition
    af Federal Highway Administration
    242,95 kr.

    Flexible linings provide a means of stabilizing roadside channels. Flexible linings are able to conform to changes in channel shape while maintaining overall lining integrity. Long-term flexible linings such as riprap, gravel, or vegetation (reinforced with synthetic mats or unreinforced) are suitable for a range of hydraulic conditions. Unreinforced vegetation and many transitional and temporary linings are suited to hydraulic conditions with moderate shear stresses. Design procedures are given for four major categories of flexible lining: vegetative linings; manufactured linings (RECPs); riprap, cobble, gravel linings; and gabion mattress linings. Design procedures for composite linings, bends, and steep slopes are also provided. The design procedures are based on the concept of maximum permissible tractive force. Methods for determination of hydraulic resistance applied shear stress as well as permissible shear stress for individual linings and lining types are presented. This edition includes updated methodologies for vegetated and manufactured lining design that addresses the wide range of commercial products now on the market. This edition also includes a unified design approach for riprap integrating alternative methods for estimating hydraulic resistance and the steep slope procedures. Other minor updates and corrections have been made. This edition has been prepared using dual units.

  • af Federal Highway Administration
    167,95 kr.

    The Federal Highway Administration (FHWA's) Climate Change and Extreme Weather Vulnerability Assessment Framework (hereafter, "the framework") is a guide and collection of resources for use in analyzing the impacts of climate change and extreme weather on transportation infrastructure. Its purpose is to identify key considerations, questions, and resources that can be used to design and implement a climate change vulnerability assessment. It gives an overview of key steps in conducting vulnerability assessments and uses in-practice examples to demonstrate a variety of ways to gather and process information. The framework is comprised of three key steps: defining study objectives and scope; assessing vulnerability; and incorporating results into decision making. The processes, lessons learned, and resources outlined in the framework are geared toward State departments of transportation (DOTs), metropolitan planning organizations (MPOs), and other agencies involved in planning, building, or maintaining the transportation system. It includes suggestions and examples applicable to a wide range of applications, from small qualitative studies to large, detailed, data-intensive analyses.

  • af Federal Highway Administration
    227,95 kr.

    The Emergency Relief for Federally Owned Roads Program, or ERFO Program, was established to assist Federal agencies with the repair or reconstruction of Federal roads, which are found to have suffered serious damage by a natural disaster over a wide area or by a catastrophic failure (23CFR668.201). The purpose of this manual is to provide federal land management agencies with guidance and instructions to apply for federal assistance under the ERFO program. Federal, tribal, state, and local governments that have the authority to repair or reconstruct federal roads may apply for ERFO funds, but only the federal land management agencies (FLMA) can apply directly as an "Applicant." The other governmental entities must apply through an "Applicant." The intent of the ERFO program is to pay the unusually heavy expenses in the repair and reconstruction of Federal roads 23CFR668.205 (a). The ERFO program is not intended to cover all repair costs nor interim emergency repair costs that are necessary to repair or reconstruct Federal roads. Agencies have the responsibility to perform emergency repairs and fund the unexpected expenditures, shift project priorities and manage reduced traffic service levels that a natural disaster can present. Emergency relief work shall be given prompt attention and priority over non-emergency work.

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