Full depth reclamation of asphalt pavements using asphalt emulsions is a process that recycles and rejuvenates the existing asphalt pavement surface, base, and sometimes, the subgrade, providing an improved underlying structure for the new asphalt pavement. This report provides guidance, standardized plans and specifications, construction inspection best practices materials testing procedures and frequencies, a performance evaluation process, and quality assurance and quality control protocols when constructing FDR projects.
The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training maintenance personnel, and identifying potential areas of cost savings and improved performance.
This research project enables CDOT to answer the question of whether or not pedestrians and bicyclists are being adequately accommodated by establishing Colorado-specific methodologies for estimating bicycle and pedestrian volumes via a limited sample of existing counts.
This report contains the documentation and supporting technical notes for a statistical model that estimates changes in the price components of the Colorado Construction Cost Index. The model contains two specifications. In the first, the composite construction index is a function of the producer prices of inputs: oil, concrete, steel, labor and equipment. In the second, the composite construction index is a function of the price of oil, wages and nationwide demand for construction services. Implementation The model has been transferred to Colorado Department of Transportation (CDOT)'s economist, who will maintain and operate it to forecast price inflation in construction costs over a thirty-year period, in support of statewide planning and programming.
Traffic noise abatement in mountain corridors can be difficult because traditional roadside barriers may be ineffective due to topography or may not fit the setting. This study examined current best practices from around the world to gather concepts for mitigating traffic noise in mountain corridors in Colorado. A literature review of prospective noise abatement actions found that noise barriers are the most effective direct noise abatement measure, although quieter pavements could have an important supporting role.
The purpose of this report is to document Accelerated Bridge Construction (ABC) techniques on IBRD (Innovative Bridge Research and Development) project 102470 for the construction of Bridge N-16-Q on State Highway 69 over Turkey Creek. The project demonstrated faster pier erection by utilizing precast pier caps to eliminate concrete cure time from the critical path in the construction schedule.
The purpose of this study is to evaluate the cost of rehabilitation techniques used on interstates, state highways, and principal arterials dating back to 2009 for use in LCCAs. The rehabilitation techniques used in this study include cold in-place recycling, hot in-place recycling, full-depth reclamation, hot-mix asphalt overlays, hot-mix asphalt mill-and-fill, and portland cement concrete pavement. Hot in-place recycling was further broken into three categories; heater remixing, heater repaving, and heater scarifying.
The advent of solar energy utilization in highway infrastructure around the country has been increasing in recent years. Right of Ways (ROWs) have several advantages for energy development such as the existing electrical infrastructure aligned with the major highways, a secured boundary, and easy maintenance access. To understand the potential impacts on driver safety, environmental resources, and maintenance operations, case studies are presented from national and international projects. Factors associated risk impacts are analyzed qualitatively as well as quantitatively. Mitigation measures are recommended to minimize the undesirable impacts in the planning, design, construction, operation and maintenance of solar array.
Following a rigid set of testing protocols, data is being collected on highway traffic noise characteristics along with safety and durability aspects of the associated pavements. This report completes a comprehensive, long-term study to determine if particular pavement surface types and/or textures can be used as quieter pavements, and possibly be used to help satisfy FHWA noise mitigation requirements.
In this study, the Regional Transportation District's (RTD's) light rail operations were examined for pollutant production and runoff. Conclusions from the study: Water leaving ballasted tracks carries only a small fraction of the heavy metals that are introduced into tracks from the light rail operations. Heavy metal concentrations at the most heavily traveled light rail station showed that pollutant concentrations were far below the regulatory limits.
This report presents information and data produced by the Colorado Department of Transportation's long-term study of Portland cement concrete pavement (PCCP) textures used within the state. The information includes vehicle accident, friction, and texture data. This information was used as the for a review of proposed revisions to the CDOT texture measurement method, CP-77, and a specification for PCCP texturing found in Sections 106 and 412 of the Standard Specifications.
The results from the research study suggest that there is a clear demand to incorporate real-time weather conditions and roadway geometric characteristics within the development of the ATM system. This model has the potential to be an accurate component of a proactive traffic management strategy to provide reliable and timely information to drivers under various adverse environments. This work could serve as the basis for a future Variable Speed Limit algorithm to be deployed on I-70.
This study applies contract bid tabulations and element-level condition records to develop element-level actions, costs for actions, transition probabilities for models of deterioration of bridge elements, and transition probabilities for improvements to elements due to actions. The study uses transition probabilities for element deterioration to compute the number of years to possible loss of safety in bridges, and to compute the number of years for inspection intervals. It examines variations in costs of actions and deterioration of elements among CDOT regions.
Adaptive signal control uses real-time data collected by system detectors to optimize signal timing for each intersection in the corridor. The use of real-time data means that signal timing along the corridor changes to accommodate the traffic patterns at any given time of the day. Test systems were set up in Greeley and Woodland Park, Colorado.
Roller Compacted Concrete (RCC) is a no-slump concrete mixture that is transported, placed, and compacted with the same construction equipment as asphalt pavement. After only nine months of service, the RCCs already showed noticeable changes in all of the selected properties tested. More tests and field inspections should be conducted in the future after a longer monitoring period to verify and validate the initial findings observed in the material properties and surface conditions of the RCC pavements.
In this study, the Regional Transportation District's (RTD's) light rail tracks were modeled to determine the Rational Method runoff coefficient, C, values corresponding to ballasted tracks. The runoff coefficient for ballasted tracks is significantly larger than the previously tabulated values for railroad yards. The higher runoff coefficient reflects the design of ballasted tracks to drain rainfall as quickly as possible.