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Most experienced trail crews try to avoid wetlands because of the construction and maintenance problems they pose. Little has been published on wetland trail construction, and materials that are available are often outmoded or are too regionally focused. By pulling this information together from our experiences, we hope to answer questions you didn't even know you had. In this manual we have described the common techniques for building a wetland trail. We have also included information on some of the more unusual materials and tools. Some of the techniques and tools we describe are suitable for wilderness situations where mechanized equipment cannot be used. Others are suitable for urban greenbelts where a wider range of techniques, material, and equipment can be used. Somewhere in between are the back-country sites where machines are permitted, but access and logistics are challenges. Although this book is written for wetland trails, the techniques described can also be used for correcting other poorly drained low areas in existing trails. The manual is written for those who are untrained and inexperienced in wetland trail construction, but those with experience may learn a few things, too.

Traffic control devices (TCDs) are very critical for the safe and efficient transportation of people and goods. The Manual on Uniform Traffic Control Devices (MUTCD), by setting minimum standards and providing guidance, ensures uniformity of traffic control devices across the nation. The use of uniform TCDs (messages, locations, sizes, shapes, and colors) helps reduce crashes and congestion, and improves the efficiency of the surface transportation system. Uniformity also helps reduce the cost of TCDs through standardization. The information contained in the MUTCD is the result of years of practical experience, research, and/or the MUTCD experimentation process. This effort ensures that TCDs are visible, recognizable, understandable, and necessary. The MUTCD is a dynamic document that changes with time to address contemporary safety and operational issues.

The purpose of the MUTCD is to establish uniform national criteria for the use of traffic control devices that meet the needs and expectancy of road users on all streets, highways, pedestrian and bicycle facilities, and site roadways open to public travel.Traffic control devices (TCDs) are very critical for the safe and efficient transportation of people and goods. The Manual on Uniform Traffic Control Devices (MUTCD), by setting minimum standards and providing guidance, ensures uniformity of traffic control devices across the nation. The use of uniform TCDs (messages, locations, sizes, shapes, and colors) helps reduce crashes and congestion, and improves the efficiency of the surface transportation system. Uniformity also helps reduce the cost of TCDs through standardization. The information contained in the MUTCD is the result of years of practical experience, research, and/or the MUTCD experimentation process. This effort ensures that TCDs are visible, recognizable, understandable, and necessary. The MUTCD is a dynamic document that changes with time to address contemporary safety and operational issues.

(PDDM Part II - Chapters 8-13) Federal Lands Highway (FLH) has developed the Project Development and Design Manual (PDDM) to provide current policies and guidance for the interdisciplinary project development and design related activities performed by FLH Divisions and their consultants. It also serves as a guide for administrators, public officials and others, both within and outside FLH, who are responsible for advancing projects through the project development process. The purpose of the PDDM is to: Provide current policies, standards, criteria and guidance for development and design of FLH projects; Be easily accessed by internal and external participants in the project development process; Be user-friendly with useful navigation and search tools; Provide immediate access to approved external references; and Be frequently updated to maintain credibility. A primary goal of the PDDM is clarifying what is expected for FLH projects and delivering an end product that meets these expectations. The previous edition of the manual has been converted from a policy/procedures hard copy format manual to a policy/best practices, interactive web-based document with electronic links. Most theory-specific procedures or recommended methods, including computer software, are included in the updated PDDM by reference only. This manual is not intended to be a technical "how to" instructional guide. The manual defines FLH policies, standards and standard practices, criteria, guidance and discretionary expectations for project development. The FLH Discipline Champions and their respective teams prepared this edition of the PDDM, with assistance from engineering consultants. The FLH Discipline Champions wish to express their appreciation to all contributors who assisted in the development of this manual, specifically the contributions of the following: FLH Division Engineers and Directors, FLH Branch Chiefs, FLH Staff, Materials furnished by other State and Federal agencies, Research publications and materials furnished by the private sector, Consultants who contributed to the preparation, and Federal land management agency partners and other reviewers.

(PDDM Part I - Chapters 1-7) Federal Lands Highway (FLH) has developed the Project Development and Design Manual (PDDM) to provide current policies and guidance for the interdisciplinary project development and design related activities performed by FLH Divisions and their consultants. It also serves as a guide for administrators, public officials and others, both within and outside FLH, who are responsible for advancing projects through the project development process. The purpose of the PDDM is to: Provide current policies, standards, criteria and guidance for development and design of FLH projects; Be easily accessed by internal and external participants in the project development process; Be user-friendly with useful navigation and search tools; Provide immediate access to approved external references; and Be frequently updated to maintain credibility. A primary goal of the PDDM is clarifying what is expected for FLH projects and delivering an end product that meets these expectations. The previous edition of the manual has been converted from a policy/procedures hard copy format manual to a policy/best practices, interactive web-based document with electronic links. Most theory-specific procedures or recommended methods, including computer software, are included in the updated PDDM by reference only. This manual is not intended to be a technical "how to" instructional guide. The manual defines FLH policies, standards and standard practices, criteria, guidance and discretionary expectations for project development. The FLH Discipline Champions and their respective teams prepared this edition of the PDDM, with assistance from engineering consultants. The FLH Discipline Champions wish to express their appreciation to all contributors who assisted in the development of this manual, specifically the contributions of the following: FLH Division Engineers and Directors, FLH Branch Chiefs, FLH Staff, Materials furnished by other State and Federal agencies, Research publications and materials furnished by the private sector, Consultants who contributed to the preparation, and Federal land management agency partners and other reviewers.

This Work Zone Best Practices Guidebook provides an easily accessible compilation of work zone operations practices used and recommended by various States and localities around the country. The Guidebook is a reference document that can be updated with new approaches, technologies, and practices for effectively managing work zones and reducing the impacts of work zones on mobility and safety as they are identified. The best practices are descriptive, not prescriptive. They describe approaches that have been successfully used by transportation agencies, along with contact information to find out more from the agency using the practice. Each organization must determine which of these practices are best suited for its particular situation, considering all the site-specific factors that affect work zone operations.

Reducing traffic congestion and improving roadway safety are high priorities for the Federal Highway Administration (FHWA). Traffic incidents are a major source of both highway congestion and safety problems. Incidents are estimated to cause approximately half of all traffic delay. Crashes that result from other incidents account for approximately 16 percent of all crashes and cause 18 percent of freeway deaths. For these reasons, FHWA strongly endorses the establishment and use of good traffic incident management. Effective transportation system management and operations depends on the aggressive management of temporary disruptions (caused by traffic incidents, work zones, weather, special events, etc.) in order to reduce the consequences of these disruptions and return the system to "full capacity." The Incident Command System (ICS) is the systematic tool for the command, control, and coordination of an emergency response. ICS allows agencies to work together using common terminology and operating procedures for controlling personnel, facilities, equipment, and communications at an incident scene. The purpose of this Simplified Guide is to introduce the ICS to stakeholders who may be called upon to provide specific expertise, assistance, or material during highway incidents but who may be largely unfamiliar with ICS organization and operations. These stakeholders include transportation agencies and companies involved in towing and recovery, as well as elected officials and government agency managers at all levels. This document may also be beneficial to public safety professionals, who are familiar with ICS but may not fully understand how ICS concepts are applicable to transportation agencies.

(Hydraulic Design Series) This document provides technical information and guidance on the hydraulic analysis and design of bridges. The goal is to provide information such that bridges can be designed as safely as possible while optimizing costs and limiting impacts to property and the environment. Many significant aspects of bridge hydraulic design are discussed. These include regulatory topics, specific approaches for bridge hydraulic modeling, hydraulic model selection, bridge design impacts on scour and stream instability, and sediment transport.

This primer is focused on the collaborative and systematic consideration of management and operations during transportation project design and development. This is termed "designing for operations." Effectively designing for operations involves the development and application of design policies, procedures, and strategies that support transportation management and operations. The consideration of operations needs during the design process requires transportation design professionals to work closely with those with expertise in transportation operations, intelligent transportation and transportation technology staff, planning, transit, freight, traffic incident management, and other practitioners from multiple agencies to fully identify, prioritize, and incorporate operations needs into the infrastructure design. This primer introduces the concept for designing for operations and describes tools or institutional approaches to assist transportation agencies in considering operations in their design procedures as well as pointing out some specific design considerations for various operations strategies.

(Hydraulic Engineering Circular No. 25) The purpose of this manual is to provide guidance on hydraulic modeling for bridges over tidal waterways. This document includes descriptions of: (1) common physical features that affect transportation projects in coastal areas, (2) tide causing astronomical and hydrologic processes, (3) approaches for determining hydraulic conditions for bridges in tidal waterways, (4) applying the hydraulic analysis results to provide scour estimates. By using the methods in this manual, better predictions of bridge hydraulics and scour in tidal waterways will result. In many cases, simplified tidal hydraulic methods will provide adequate results. However, when the simplified methods yield overly conservative results, use of the recommended modeling approaches will provide more realistic predictions and hydraulic variables and scour.

The purpose of this document is to assist organizations and their leaders in implementing and sustaining regional traffic incident management programs, both by examining some successful models, and by considering some of the lessons learned by early implementers. There is some form of incident management activity in most major and many mid-sized urban areas. Typically this involves each agency carrying out its own responsibilities, with primarily working-level and middle-management administrative teams to provide coordination with the other agencies who are also involved in their own aspects of managing incidents. Such a situation not only achieves less than the full potential benefit, but also leaves open many risks for failure within individual agencies or on a broader scale. The objective of this document is to present a framework for developing what is missing in almost every urban area-a formal multiagency traffic incident management program, with endorsement by, participation from, and coordination by senior agency management, and which includes all of the participating agencies. Formalizing the incident management effort-turning it into an incident management program-involves such steps as developing a written and endorsed strategy and a plan to implement the strategy; identifying and building support from a full complement of stakeholders and with the public; gaining support and ongoing participation in program direction from agency senior executives; documenting the respective roles and responsibilities of participants; establishing program goals and objectives and evaluating performance on these; establishing incident management as a major mission within and between the participating agencies; and "mainstreaming" of funding for incident management into the traditional transportation planning process.

(Hydraulic Engineering Circular 22, Third Edition) This publication provides a comprehensive and practical guide for the design of storm drainage systems associated with transportation facilities. Design guidance is provided for the design of storm drainage systems which collect, convey, and discharge stormwater flowing within and along the highway right-of-way. Methods and procedures are given for the hydraulic design of storm drainage systems. Design methods are presented for evaluating rainfall and runoff magnitude, pavement drainage, gutter flow, inlet design, median and roadside ditch flow, structure design, and storm drain piping. Procedures for the design of detention facilities are also presented, along with an overview of storm water pumping stations and urban water quality practices.

The "Standard Specifications for the Construction of Roads and Bridges on Federal Highway Projects (FP)" is issued primarily for constructing roads and bridges on Federal Highway projects under the direct administration of the Federal Highway Administration. It is also used by the U. S. Forest Service and other Federal agencies on their projects. These specifications are cited as "FP-14" indicating "Federal Project" Standard Specifications issued in 2014 and contain both United States Customary and Metric units of measure.

Federal-Aid highway funds are authorized by Congress to assist the States in providing for construction, reconstruction, and improvement of highways and bridges on eligible Federal-Aid highway routes and for other special purpose programs and projects. Through the Federal Lands Highway Program, funding is provided for improving access to and within National Forests, National Parks, Indian Lands and other public lands. The guide is intended to provide basic information for FHWA and State personnel involved in the administration of the Federal-Aid Highway Program. It is not intended to be an eligibility guide, but contains basic descriptions and historical information on active and inactive programs. This guide should be of interest to FHWA, State highway agencies, local governments, and private sector personnel interested in a basic understanding of Federal-Aid programs, projects, or other program characteristics. In addition to basic information, sources of additional information are provided.

Experimental results and analyses are given in this report on bridge abutment scour in compound channels. Experiments were conducted in a laboratory flume with a cross section consisting of a wide floodplain adjacent to a main channel. The embankment length, discharge, sediment size, and abutment shape were varied, and the resulting equilibrium scour depths were measured. Water-surface profiles, velocities, and scour-hole contours were also measured. In the report, a methodology is developed for estimating abutment scour that takes into account the redistribution of discharge in the bridge contraction, abutment shape, sediment size, and tailwater depth. The independent variables in the proposed scour formula are evaluated at the approach-channel cross section and can be obtained from a one-dimensional water-surface profile computer program such as the Water-Surface Profile Program (WSPRO). The proposed scour evaluation procedure is outlined and illustrated, including consideration of the time required to reach equilibrium scour. The proposed methodology is applied to two cases of measured scour in the field. Research objectives include: Investigate the effects of flow distribution, as affected by abutment length, on clear-water abutment scour in a compound channel for abutment lengths that terminate on the floodplain as well as encroach on the bank of the main channel. Quantify the effects of floodplain sediment size on abutment scour. Explore the influence of abutment shapes, including wingwall, vertical-wall, and spill-through shapes, on equilibrium scour-hole depth and scour-hole form. Determine the relative importance of the live-bed scour case compared to the clear-water case when there is sediment transport in the main channel and the abutment encroaches on the main channel. Combine the experimental results into a methodology for assessing field abutment scour and test it on available field data.

This report provides a guideline to estimate the staffing and resource needs required to effectively operate and maintain traffic signal systems. The results of a survey performed under this project, as well as a review of the literature and other surveys indicated that agencies achieving a high level of signal system performance do so under a wide variety of conditions such as agency size, geography, system complexity and traffic conditions that do not adhere to the typical level of documented resource requirements. Accordingly, a set of performance-based criteria were developed to define requirements. The performance-based criteria are focused on establishing realistic and concise operations objectives and performance measures.

The South Dakota Department of Transportation (SDDOT) and the Federal Highway Administration (FHWA) collaborated on a research study to determine the effects of a number of inlet geometry choices on culvert hydraulic efficiency. This study is a response to the large number of culverts that are installed in the United States and the fact that most of the current guidelines on culvert hydraulics are based on research completed more than 20 years ago. The objectives of this study were to: Determine optimum edge conditions for wingwalls; Determine the effects of inlet geometry on flow capacity of single and multiple barrel culverts with optimized edge treatment of wingwalls; Determine effects of the span-to-rise ratio on flow capacity with various inlet geometries; Determine the effects of skew on flow capacity of box culverts.

The goal of bridge inspections is to assess the safety of bridges on a regular basis so that any deficiencies will be identified and corrected. Given the large number of bridges over water in any State, bridge inspectors must inspect the superstructure, substructure, and waterway of each bridge in a short amount of time. A typical range of time for bridge inspections is 15 minutes to 2 hours, depending on the complexity and condition of the bridge. A more detailed inspection might ensue if a deficiency is detected. In the case of waterways and erosion, a hydraulic engineer might visit the bridge to assess the situation in greater detail. For either of these levels of inspection, and given the very limited right-of-way at most bridges, the inspector or engineer typically will not walk more than a few hundred feet upstream or downstream. Most inspectors do not leave the bridge right-of-way. Thus, a method is needed for systematically assessing the stability of the stream channel with respect to the bridge. The ability to assess channel stability in the vicinity of bridges also is needed for designing road crossings, and for mitigating and predicting erosion at those structures. Bridge failures due to geomorphic or regional instability have been experienced in many locations in the United States and elsewhere. Federal Highway Administration (FHWA) guidelines for stream stability and erosion at bridges describe examples of problems at bridges caused by regional channel degradation and lateral bank changes. These guidelines require that engineers assess channel instability in their bridge assessments. However, for most bridges, only a preliminary assessment can be conducted due to time and money constraints. The objective of this study was to expand and improve previous rapid stability assessment methods to include additional factors, such as major physiographic units across the United States, range of bank materials and complexities, critical bank heights, stream type and processes, sand bed streams, and in-channel bars or lack of bars.

Hydraulics and scour hazards cause over half of the bridge failures in the United States and have been identified by State bridge authorities as one of the top issues in bridge design and maintenance. Current pier scour design in the United States is mainly based on the Colorado State University (CSU) equation, which is described in Hydraulic Engineering Circular No. 18 (HEC-18). A recent evaluation of bridge scour research indicated a need to change the current method because substantial advances have been made in understanding pier scour processes. The evaluation compared several methods and considered which methods effectively included the variables now believed to determine pier scour characteristics. The objective of this report is to describe a new method for estimating pier scour based on an understanding of the flow-structure-sediment interactions and to address the weaknesses in earlier methods. This research focuses on clear-water scour at singular piers in non-cohesive sediment mixtures. The approach was to review previous pier scour methods, formulate an improved model for scour formation, and evaluate the new model using laboratory and field data.

The Highway-Rail Crossing Handbook, 3rd Edition (Handbook) has been prepared to disseminate current practices and requirements for developing engineering treatments for highway-rail grade crossings (referred to herein as "crossings"). The Handbook is intended to provide practitioners of all levels of knowledge and experience with critical background information and "noteworthy practices" consistent with the 2009 Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) and more recent guidance developed by recognized subject matter experts. This edition constitutes a substantial update to and revision of the 2007 Handbook and efforts have been made to reorganize the contents.

This Guide is intended for writers that develop specifications for the Federal Highway Administration's (FHWA) Federal Lands Highway Program (FLH). This Guide is to promote and facilitate the writing of specifications that conform to the five Cs of specification writing - clear, concise, complete, correct, and consistent. Adherence to the guidance provided in these chapters and Chapter 9.4.11 of the FLH's Project Development and Design Manual will help writers develop well-written specifications for use with the Standard Specification for Construction of Road and Bridges on Federal Highway Projects (FP). The FP in and of itself is a good example of proper style and format. This document contains guidelines to help writers develop specifications for the Federal Highway Administration's Federal Lands Highway program. Topics addressed include: Specification writing style; Organization and format, Proper terminology and phrasing; Capitalization and abbreviation; and Punctuation and grammar rules.

This report provides an overview of practices related to developing and sustaining a Regional Traffic Signal Operations Program. The purpose for a Regional Traffic Signal Operations Program is to provide regional partners a formal framework to collectively manage the signal system performance for efficiency and consistency. A key benefit of a regional program is the development of projects that are of a magnitude that they can be included in a regional or state transportation improvement program (TIP). There are many benefits to the development of a regional traffic signal management and operations program. Agencies and users benefit from regional traffic signal operations programs as planners, engineers, and operators can provide an effective and efficient traffic signal system to the public and also provide higher levels of customer service without increasing costs. Additionally, by sustaining collaboration, regional operators can demonstrate to the public and elected officials that progress is being made on community goals, which then can be leveraged for future funding. Agencies and jurisdictions within a region that use a common framework for developing and establishing expectations, managing resources, and building relationships will result in more successful systems both individually and region-wide.

The Federal Lands Highway (FLH) 2009 Strategic Implementation Plan (SIP) included an initiative to research and document applicable, efficient processes for transferring funds to and from other agencies. This includes our use of reimbursable authority to advance funds to other agencies when appropriate. This guide will ensure stewardship of the funds entrusted to FLH and our partners. The guide is designed to promote a uniform approach by our Division offices and will minimize the inefficiencies and delays experienced in the past. Finance staff, programs staff, and project managers are the intended users of this guide. It is intentionally written in user-friendly language. We have taken some liberty with the title "Funding Transfer Guide." Generally under government finance and accounting provisions, the term "transfer" is associated only with accounts either within or between Federal agencies. The Office of Chief Counsel and the Office of the CFO have agreed to allow us to use common terms to keep this document comprehensible for the FLH practitioner. At the same time, we agree it is important to point out variations from more proper finance terminology, where appropriate. Through our multidisciplinary efforts over the last year, we have assimilated a practical guide to help FLH deliver a successful program in the future. This guide should be used for transferring project funds only. In the rare case where GOE or management overhead funds require transfer, you may use the same process as presented here (e.g., agreement with GSA for doing a building modification). Please coordinate GOE or management overhead transfers with your Planning & Programs office and Acquisitions office for guidance. These guidelines do not address HQ procedures for allocating funds to our Federal partners. Nor do they address the process for transferring other Federal Aid funds to our partners (e.g., High Priority Program, Scenic Byway, Transportation Enhancements). Fund transfers fall under two categories - transferring funds to FLH and transferring funds from FLH.

Research and experience has shown that retiming traffic signals is one of the most cost- effective tasks that an agency can do to improve traffic flow. Traffic flow improvements of up to 26 percent have been reported1. In spite of this potential, many Traffic Engineers simply do not have the budgetary resources to conduct a signal retiming program using the conventional methods.

The vision of the Every Day Counts Adaptive Signal Control Technology (ASCT) Initiative is to mainstream the use of adaptive signal control technology. "Mainstream the use of" suggests that when traffic conditions, agency needs, resources and capability support the use of ASCT it should be implemented. These model systems engineering documents support the process of exploring the need for ASCT and articulating a set of requirements that enable agencies to specify, select, implement and test adaptive signal control technology. Over the last two decades a significant number of adaptive systems have been deactivated well before the end of their useful life due either to a lack of adequate resources or agency capability to support system operation and maintenance, or in some cases a failure to properly align agency and system operations objectives. The risks associated with ASCT implementation are significant. This document helps accomplish the tasks of clarifying objectives, identifying needs and defining constraints by leading the reader through a series of questions. The outcome of selecting and tailoring the sample responses will be a set of clear and concise statements to formulate the required systems engineering documentation. By following this guidance an agency can expect to produce the following documents: Concept of Operation, System Requirements, Verification Plan, Validation Plan.

Agencies can realize a range of tangible benefits from participating in multi-agency collaborative efforts for regional transportation operations. These benefits include access to funding and other resources, improvements in agency operations and productivity, and outcomes that help agencies achieve their mobility and safety goals. This manual uses nine collaborative efforts across the U.S. to illustrate the tangible benefits gained through key strategies such as sharing resources and expertise, performing joint operations, using common operations procedures, and exchanging real-time information. The manual includes a six-step process to allow agencies to estimate their benefits of collaboration.

This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.

Rapid advances in information processing and communications technology have created new opportunities for transportation professionals to deliver safer and more efficient transportation services, and to respond proactively to increasing demand for transportation services in many areas and mounting customer expectations from coast to coast. However, many of these new opportunities are predicated upon effective coordination between organizations - at both an institutional and technical level. To encourage and enable this coordination, the USDOT has developed the National ITS Architecture and related tools to help identify and exploit these opportunities for cost-effective cooperation. This document is one such tool -- it describes how to develop a regional ITS architecture, which will be a cornerstone of planning for effective interagency coordination and for deployment and operation of technology-based projects. In 1997, Congress passed the Transportation Equity Act for the 21st Century (TEA-21) to address the need to begin to work toward regionally integrated transportation systems. In January 2001, FHWA published a rule (ITS Architecture and Standards) and FTA published a companion policy to implement section 5206(e) of TEA-21. This Rule/Policy seeks to foster regional integration by requiring that all ITS projects funded from the Highway Trust Fund be in conformance with the National ITS Architecture and officially adopted standards. "Conformance with the National ITS Architecture" is defined in the final Rule/Policy as using the National ITS Architecture to develop a "regional ITS architecture" that would be tailored to address the local situation and ITS investment needs, and the subsequent adherence of ITS projects to the regional ITS architecture. This ITS Architecture and Standards Rule/Policy continues under the current SAFETEA-LU federal transportation act. SAFETEA-LU emphasizes, among other things, congestion mitigation, real-time system management information systems, and planning and approaching transportation operations from a regional perspective. In Section 1201.c of the SAFETEA-LU legislation, State and local governments are required to address information needs and data exchange associated with highway and transit information and monitoring systems when developing or updating their regional ITS architectures. In addition, Section 6001 of SAFETEA-LU mandates that large metropolitan areas (population greater than 200,000) establish a congestion management process (CMP) that provides for effective management and operation of the transportation system within the region. The CMP is something that can be greatly enhanced by receiving archived ITS travel data, among other data points, generated by a deployed ITS network. During the stakeholder identification process, the ITS architecture should include this planning need for ITS data throughout the region. ITS architectures provide support in these areas as stakeholders analyze their implementation. This document is a guide for transportation professionals who are involved in the development, use, or maintenance of regional ITS architectures. The document describes a process for creating a regional ITS architecture with supporting examples of each architecture product. In its discussion of the uses of the regional ITS architecture, the document presents an approach for mainstreaming ITS into the transportation planning and project development processes.

This handbook was created to provide individuals responsible for managing and implementing Traffic Signal, and Freeway Management programs with an understand of the basic technologies of telecommunications. The handbook provides a brief look at the history of telecommunications so that its readers may gain an understanding of why various processes exist, and how the technologies evolved. The handbook is not designed to be used as a specification for telecommunication systems. The technologies associated with telecommunications are in a constant state of change. This handbook was written over a two year period between August, 2002 and June 2004. During this time, a number of emerging technologies began to reach maturity. The most significant of these, wireless internet access, and voice over IP have caused the major carriers (telephone companies) to announce the construction of new facilities to provide "Internet Telephony" services. Readers of this handbook should gain an understanding of the basic technologies underlying most telecommunications systems designed to transmit both voice and data information.

This report presents the summary and synthesis of the various components of the experimental study entitled "Effects of Gradation and Cohesion on Bridge Scour" conducted at Colorado State University between the dates 1991 through 1996. As a result of this effort, in excess of 250 new pier scour data was collected and a new equation was developed expressing pier scour in terms of the dimensionless excess velocity factor, flow depth, pier diameter and a correction factor for the coarse fractions present in mixtures was derived. The new method was tested with available data from previous research. This equation shows that gradation effects are not constant through the entire range of flow conditions but vary with flow intensity. Additionally, a new method to adjust FHWA's Colorado State University pier scour equation for initiation of motion and sediment size was developed. Abutment scour experiments resulted in over 384 new points and 2 new abutment scour equations. The first equation was derived from a 0.1 mm uniform sand mixture and defines an envelope relationship. The second equation applies to mixtures with coarse fractions. A coarse size fraction compensation factor Wg is presented to account for the presence of varying amounts of coarse material in sediment mixtures under different dimensionless flow intensities. These new equations represented the experimental data accurately but have not been tested with field data. Effects of cohesion on pier and abutment scour were studied systematically, and in excess of 200 new data points were collected covering a range of flow and cohesive parameter values. Relationships were developed to explain the variability of bridge scour in cohesive materials for various cohesive material properties.