Many new innovative technologies have been funded through the CTIP program. Publications of these technologies and projects have been completed in collaborative partnership with the Federal Highway Administration and are provided in the Publications Library. Recent publications are highlighted below.
This guidebook provides an approach for practitioners to integrate sustainability into the planning, design, and construction of roadway projects and is intended to be compatible with an owner's existing technical guidance for project development processes. The approach in this guidebook assumes that appropriate system-level planning efforts are complete and a specific project is identified for development. The approach is applicable to the project development phases of the project lifecycle, which include project planning, design, and construction.
This guidebook focuses on an approach for integrating sustainability rather than providing a set of sustainable solutions for practitioners to choose from that could quickly become outdated. Providing the approach, instead of the solutions, gives practitioners the tools they need to integrate sustainability and ensures that the guidebook remains current and relevant while sustainability technology and best practices continue to evolve. View publication »
The roadside represents the interface between the roadway and the surrounding environment, and plays an important role in protecting the larger ecosystem. Roadsides are dynamic environments that require unique treatments and restoration approaches. This guide presents an integrated and holistic approach to incorporating sustainable solutions into disciplines such as hydraulic design, geotech, aesthetics and vegetation, among others. The intent of this research is not to create a new design process, but rather to incorporate recommendations into the existing design process. The goal is to raise awareness about the trade-offs inherent in designing a sustainable roadside so that these issues are addressed early-on in project development. A checklist of sustainability strategies is included in this guidebook as a tool within the project development process. View publication »
Climate variability is widely accepted as fact in the scientific community; however, the extent of change and the associated outcomes—including sea level rise, changes in temperature, and changes in precipitation—vary depending on the scenario assumed. There is strong evidence that some climate changes are already occurring and that additional, more significant, changes are likely this century. These findings have important ramifications for the professionals at the Federal Highway Administration (FHWA). First, existing infrastructure could be exposed to greater risk of damage or destruction as conditions change. Second, the designs for new infrastructure should consider taking projected climatic changes into account; no longer can design criteria based only on past observations be relied upon to predict future design conditions.
Future scenarios are variable and uncertain making the determination of risk problematic. Given these concerns, the goals of this document are to (1) help FHWA staff assess the risks and impacts that projected climate variability could have on their existing assets and (2) describe how climate variability should be addressed in the planning and designing of new assets. This document is not intended to set policy. View publication »
The use of sustainable practices by the Federal Lands Highway Program (FLHP) in design and construction can be difficult because (1) they may be new or different and not part of the existing design/construction process, or (2) there is no effective broad-based means of comparison or quantitative assessment in this area. As a result, sustainable roadway design and construction practices may be overlooked or implemented piecemeal without full consideration of their lifecycle impacts and interrelationships. It is also difficult to communicate sustainable features to the general public and to create a process to include such features that encourages innovation by all project personnel and stakeholders. A compilation of sustainability best practices along with a system capable of quantifying these practices would allow for more informed decisions regarding roadway design and construction sustainability, better dissemination of ideas and more straightforward communication regarding their use and benefits. This project:
Traffic Monitoring: A Guidebook discusses different approaches to traffic monitoring and helping decisions to be made are based on the quality of the traffic data being collected and how well that traffic data reflects the actual events that are occurring. This guidebook should aid the user in developing a basic understanding of traffic data collection principles and procedures. This guidebook will provide an overview of traffic monitoring through simple descriptions, which explain the various basic concepts related to a successful traffic monitoring program. Furthermore, this document investigates some of the challenges associated with a traffic monitoring program including variability in traffic, adjustment factors, and strategies for assisting with under-funded programs. This guidebook does not attempt to cover every aspect and detail of traffic monitoring but provides a starting point that leads the user to a successful traffic monitoring program. View publication »
Traffic monitoring in recreational areas is often challenged by distinct traffic and roadway characteristics and the multitude of agencies responsible for the management of Federal lands and/or the collection of supporting traffic data. These challenges are exacerbated by a lack of consistent procedural guidance; existing national traffic monitoring guidelines lack sufficient direction and detail for recreational travel. In an effort to improve/lend consistency to traffic monitoring in recreational areas, the Coordinated Technology Implementation Program tasked the Office of Federal Lands Highway-Federal Highway Administration (FHWA) with conducting an assessment of the nationwide practices for recreational traffic data collection. A review of pertinent literature related to recreational traffic data collection was conducted. A targeted survey of various State and local agencies responsible for traffic monitoring was administered. A workshop focused on traffic monitoring in recreational areas was also conducted. Key findings from these activities are briefly described herein. View publication »
Chemical treatment systems (CTS) are implemented in areas where traditional, physical erosion and sediment control practices will not meet water quality goals for construction site runoff. The purpose of CTS is to reduce the amount of suspended sediment which would be released using conventional erosion control systems. The primary mechanism is the introduction of chemical flocculants into runoff, resulting in a binding of the suspended clays and silts together into larger particles which settle more quickly or can be fi ltered from the stormwater. Flow control through CTS is of vital importance for the proper dosing of stormwater runoff. All normal hydrologic analyses must be done to insure that reasonable peak flows are accounted for along with typical flows from designed storm events. Once analysis is adequately addressed, then the project can deal with the complexities of design and dose rate requirements.
The overall objectives of this book are twofold. First, it is designed to provide a technically credible basis for best management practices for the use of CTS for turbidity reduction on road construction projects. Secondly, it is designed to identify the most important variables to address when selecting chemical treatment best management practices for a particular site. View publication »
In an effort to deploy the warm mix asphalt (WMA) technology to Federal Lands Highway (FLH) and cooperating agencies, a Coordinated Technology Implementation Program (CTIP) proposal was approved by agency representatives. This CTIP project allowed FLH to take the lead in working with our client agency and contractors to evaluate the viability of warm mix technology as a standard construction practice. The demonstration evaluated two diff erent WMA technologies (Advera and Sasobit) on a construction project on the East Entrance Road of Yellowstone National Park. The mixtures were placed in August/September 2007. View publication »
The purpose of transportation asset management is to meet life-cycle performance goals (safety, mobility, preservation, economics, and environmental aspects) through the management of physical assets in the most cost-effective manner. Geotechnical asset management can be incorporated into the broader practice of transportation asset management. Currently, most agencies manage geotechnical features on the basis of "worst first" conditions, reacting to failures and incurring significant safety, mobility, environmental, and intangible costs. The goal of geotechnical asset management is to implement project planning and selection on the basis of "most-at-risk" for the asset class with consideration of collective and site specific risks throughout the life cycle. Geotechnical features that can affect the performance of a transportation system include retaining walls, unstable slopes, rockfall sites, embankments, and tunnels. These features can be treated as physical assets of the system and managed like other assets of the system. While not every geotechnical feature exists in agency, those that do can be combined into a single asset class to simplify asset management procedures. Although likely on the high end of expectation, some studies indicate a life-cycle cost savings of up to 60 to 80 percent after the implementation of geotechnical asset management. The geotechnical asset management plan should be based on agency performance goals and integrate risk and life-cycle analysis. It is important to note geotechnical asset management will only be successful when all features that create risk are included. Risk management allows for the probability and consequences of events to be evaluated, which is essential for the integration with agency performance goals. Federal Land Management Agencies can implement geotechnical asset management with a relatively modest investment and using existing resources to assess geotechnical features in a multi-tier, risk-based approach. There is an agency cost associated with inaction on geotechnical asset management. View publication »
Drilled shafts are increasingly being used in supporting critical structures, mainly because of their high-load supporting capacities, relatively low construction noise, and technological advancement in detecting drilled shaft anomalies created during construction. The critical importance of drilled shafts as foundations makes it mandatory to detect the size and location of anomalies and assess their potential effect on drilled shaft capacity.
Numerical analysis was conducted using Pile-Soil Interaction (PSI), a finite element analysis program to assess the effect of different anomalies on the axial load capacities of drilled shafts in soils ranging from soft to extremely stiff clay and loose to very dense sand. The investigation included the effect of anomalies of various sizes and lengths on both structural and geotechnical capacities. The analysis results indicate that the drilled shaft capacity is affected by the size and location of the anomaly and the strength of the surrounding soil. Also, nonconcentric anomalies significantly decrease the structural capacity of a drilled shaft under axial load. The resulting drilled shaft capacity then equals the smaller one of the two capacities: structural or geotechnical. View publication »
LiDAR (Light Detection and Ranging), also often referred to as "3D laser scanning", is an emerging three-dimensional mapping technology that employs a laser and a rotating mirror or housing to rapidly scan and image volumes and surficial areas such as rock slopes and outcrops, buildings, bridges and other natural and man-made objects. Ground-based or terrestrial LiDAR refers to tripod-based measurements, as opposed to airborne LiDAR measurements made from airplanes or helicopters. The purpose of this report was to determine whether the new technology of ground-based LiDAR could assist FHWA with highway rock slope stability. This report includes discussions of currently available LiDAR hardware and software, the current state of LiDAR for highway geotechnical applications (rock mass characterization, rock fall characterization, as-built 3D measurements), best practices for field scanning and for point cloud data processing, and expected trends in the industry in the near future. It is shown in this report that some of the most important types of geotechnical information for rock slope stability that is currently being collected by hand can be acquired from LiDAR point clouds and associated digital images. This includes detailed information about rock discontinuity orientation, roughness, length, spacing and block size. In many cases, this information can be automatically acquired using currently available point cloud processing software. There are advantages to using LiDAR for collecting this information, including improved safety, accuracy, slope access, and speed of analysis. It is recommended that LiDAR be utilized for future highway slope stability projects. View publication »