Infiltration-induced landslides are common hazards to roads in Colorado. A new methodology that uses recent advances in unsaturated soil mechanics and hydrology was developed and tested. The approach consists of using soil suction and moisture content field information in the prediction of the likelihood of landslide movement. The testing ground was an active landslide on I-70 west of the Eisenhower/Johnson Memorial Tunnels. Results indicate that the unique hydrology of the site is a key component in its stability and considering the whole water basin and not just the failure area is important.
This research evaluates the effectiveness of the SH 9 Colorado River South Wildlife & Safety Improvement Project, including two wildlife overpasses, and five wildlife underpasses connected with 10.4 miles of wildlife exclusion fencing in Grand County, CO. The project was designed to improve driver safety while allowing for wildlife movement across the road. This study uses motion-activated cameras and WVC crash and carcass data to determine how successful the mitigation measures are. In addition to the crossing structures, deer guards, escape ramps, pedestrian walk-through gates and the fence end are being monitored.
The U.S. Geological Survey (USGS), in cooperation with the Colorado Department of Transportation, determined the peak discharge, annual exceedance probability (flood frequency), and peak stage of two floods that took place on Big Cottonwood Creek at U.S. Highway 50 near Coaldale, Colorado on August 23, 2016, and on Fountain Creek below U.S. Highway 24 in Colorado Springs, Colorado on August 29, 2016.
The objective of the study was to validate the performance of blocked-faced Geosynthetic Reinforced Soil (GRS) wall and to validate the Colorado Department of Transportation's (CDOT) decision to waive the positive block connection for closely-spaced reinforcement. Contrary to conventional wisdom, the GRS wall measurements of this study demonstrated that facing pressure decreases as load increases. This counter-intuitive fact is due to the decrease of compaction-induced stress (CIS) with increased load. Therefore, if a GRS wall survives compaction, it survives indefinitely.
This research report documents the findings of an investigation into automated temporary traffic control device (TTCD) deployment and retrieval technologies. The researchers found that some automated TTCD deployment and retrieval products may reduce one or more types of worker risk while increasing other types of risk. A fully automated product has the potential for the greatest risk reduction overall, but also has a much higher cost than less complex systems.
The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical processes causing deterioration are capable of supplementing purely statistical models and addressing limitations associated with bridge inspection data and statistical methods. A review of existing analytical models in the literature was conducted. A mechanistic model was developed to predict corrosion and concrete cracking as a function of material and environmental inputs.
In late 2016/early 2017 the Colorado Department of Transportation (CDOT) conducted an operational pilot of the Road Usage Charge (RUC) concept as a possible transportation funding replacement to the state gas tax. The Colorado Road Usage Charge Pilot Program (RUCPP) involved a total of 147 participating vehicles that used one of three mileage-reporting mechanisms to record miles traveled and simulate fees based on that travel. Overall support for the operational pilot and the RUC concept itself remained high among pilot participants and there were no major technical issues encountered. A number of policy-related issues were identified throughout the course of the pilot. This report provides a summary of the RUCPP.
Crack sealants are often utilized as a preservation tool in asphalt pavements. When a hot mix asphalt overlay is placed on top a pavement containing crack sealants, a bump and additional transverse cracks sometimes occur in the new asphalt overlay. These bumps and sometimes, transverse cracks are initiated during breakdown rolling and become progressively more severe upon further compaction. This paper presents results of a five-year study designed to identify factors that relate to the appearance of these bumps and consequent cracks.
The Colorado-specific safety knowledge base, developed and effectively applied in the design process at CDOT, is not yet used to inform the planning process. This report transfers the use of these Colorado-specific, predictive and diagnostic tools to the transportation planning process. It develops a proposed methodology for the Explicit Consideration of Safety in the Transportation Planning Process by focusing on science-based and data-driven project selection, which considers susceptibility to cost-effective correction, rather than simply observed frequency and severity of crashes. This methodology will aid in ranking and prioritizing safety aspects of projects in concert with other attributes, such as mobility, air quality, noise, etc. It effectively translates state-of-the-art safety analysis techniques into an applied, practical methodology that transportation planners and practicing engineers can use.
