The purpose of this study was to determine the impact of a magnesium chloride-based deicer, a sodium chloride-based deicer, and the major salts contained in these deicers on seed germination and seedling growth and development of fifteen species of grasses and forbs native to Colorado. Seven of the fifteen species performed well at the low and medium concentrations of the salts and solutions; these are plants that can likely germinate in roadside areas.
The overall conclusion of the study is that application of magnesium chloride deicer having a chemical composition and application rate similar to those of 1997-98 is highly unlikely to cause or contribute to environmental damage at distances greater than 20 yards from the roadway. Even very close to the roadway, the potential of magnesium chloride deicer to cause environmental damage is probably much smaller than that of other factors related to road use and maintenance, including pollution of highway surfaces by vehicles and use of salt and sand mixtures to promote traction in winter. Magnesium chloride deicer may offer net environmental benefits if its use leads to a reduction in the quantity of salt and sand applied to roadways. The environmental safety of magnesium chloride deicer depends, however, on low concentrations of contaminants and avoidance of rust inhibitors containing phosphorus. Appropriate specifications for vendors and routine testing can insure the continued environmental acceptability of magnesium chloride deicers. Deicers provided by vendors should be monitored independently by CDOT for chemical characteristics. Any significant changes in processing or source material should be disclosed by the vendor. Colorado-based specifications should be developed for vendors. Independent specifications for low elevation could be developed, or the more stringent high elevation specifications can be applied to all purchases.
Discusses the highway and landscape variables that highway planners/designers should consider when choosing the best locations for mitigation that helps medium- and large-sized mammals cross highways safely."
The Greening Government Research Project is Phase 1 of a two-phased research approach to identify how CDOT can achieve the goals and objectives mandated in Governor Ritter's recently signed executive orders on greening state government.
This report investigates the impact of highways and landscape connectivity in Colorado. To do so, it describes three complementary research questions. Given the threat of roads to both wildlife populations and human safety, describing the distribution of animal-vehicle collisions (AVC) is a necessary step in understanding potential roadway impacts.
Cost-effective strategies were developed and identified to CDOT Highway Maintenance Managers to reduce rest area operational costs while conserving finite natural resources. Initial cost analysis indicates that reduced operational costs can be realized by implementing water conservation practices (waterless urinals, water harvesting, irrigation, energy conservation and alternative energy practices, and re-use and recycling of solid waste and landscaping transition toward xeriscape practices).
The environmental discussion has been developed to assist internal and external users who want an overview of the transportation decision-making process and a better understanding of the environmental considerations contained in that process.
The objective of this project was to assess the efficacy of post-fire ground treatment in mitigating erosion and runoff on soil slopes subjected to wildfires. This objective was achieved through physical slope-model experiments and discrete element method (DEM) modeling. Model simulations indicated that an increase in the root network inhibited particles dislodgement and decreased downslope movement of particles.
Mount Evans Highway (SH 5) has been severely damaged by permafrost degradation and freeze-thaw processes. We assessed the effects of the current roadway configuration on the permafrost, hydrologic processes, vegetation, and soils of the Summit Lake Park wetland complex. We also reviewed and synthesized available literature to develop design recommendations for mitigating permafrost degradation, thaw-induced subsidence and frost damage, and hydrologic alterations to alpine wetlands. The existing roadway has profoundly altered permafrost conditions, hydrological processes, and wetland plant communities.
Due to concerns that the hydrologic regime of the wetland complex in and around Summit Lake Park has been significantly altered by development of State Highway 5 (SH 5), a field study of the hydrology, soils, and vegetation above and below the roadway was initiated in 2018. The objectives of this study are to investigate the natural hydrologic processes and vegetation up-gradient from SH 5, and how they may be impacted in down-gradient areas. A review and synthesis of the road design elements that mitigate the effects of freeze-thaw and permafrost degradation, as well as minimize hydrologic disruption to adjacent wetlands is also included.
Public transit is an integral part of Colorado's multimodal transportation system providing mobility to thousands of residents and visitors throughout the state. Not only does transit connect residents, employees, and visitors to major activity centers for jobs, schools, shopping, medical care, and recreation, but it also promotes greater personal independence. Provision of transit services contribute greatly to the economic, social, and environmental health of the state and provide many benefits to individuals and communities in both rural and urban areas from fostering economic development along routes and at station locations to creating mobility options for all.
This project aims to assist CDOT with the initial implementation of Section 118 of Colorado HB 21-1303, "The Buy Clean Colorado Act". The bill requires contractors to submit Environmental Product Declarations (EPDs) for asphalt and asphalt mixtures, cement and concrete mixtures, and steel installed on CDOT projects. Ultimately, the bill instructs CDOT to establish greenhouse gas (GHG) emission limits for these materials, and contractors on CDOT construction projects will need to comply with the limits established by CDOT. The objectives of this study were to assess the current state-of-the-practice of EPDs in construction material manufacturing; to educate stakeholders regarding life cycle assessment (LCA) and EPDs; and to help develop protocols uniquely suited to Colorado that CDOT and material producers can use to integrate EPDs into the framework of Buy Clean Colorado.
