In recent years, prestressed concrete bridges have dominated the bridge type selection processes in Colorado. This can be attributed to a lack of steel mills combined with a strong presence of precast fabricators in the region. In addition, a lack of readily available economical and innovative procedures to design and construct steel bridges has hindered the industry in certain areas such as Colorado. During this research it was identified that designing steel girders as simply supported for the non composite dead loads and continuous for composite dead loads and live loads would provide economy. A preliminary girder selection software was created using this design procedure. The software takes user inputted data, such as span length, width, number of girders along with various other design inputs, and displays the lightest wide flange beam size that would support the loads using AASHTO LRFD Design Specifications. Using the girder selection software, design charts and tables were created to outline structural steel weight to span length and number of girders. The design charts will aid the bridge type selection process by giving designers an accurate measurement of minimum steel requirements for numerous one, two, and three span steel bridges.
Roadside vegetation is exposed to a variety of biotic and abiotic stresses that can impact plant health. Drought, pollution, disease, insects, lack of nutrients, and roadbed management practices may potentially act alone or synergistically to adversely affect plants in proximity to the roadside. To date, little published research documents the impacts of certain deicers on vegetation in relationship to other potential stresses. This study provides an ecological impact assessment of factors affecting the health of roadside vegetation in the state of Colorado including potential biotic and abiotic plant stressors and deicer applications.
Route optimization is a method of creating a set of winter highway treatment routes to meet a range of targets, including service level improvements, resource reallocation and changes to overriding constraints. These routes will allow the operator clear the pavement in a timely and efficient manner, reducing wastage and utilizing resources to their best effect.
Due to budget challenges, Colorado is looking for alternative funding sources for the operation and maintenance of its interstate safety rest areas (SRAs). As CDOT continues to close rest areas due to tight budgets, it should look for alternatives to fund their operation and maintenance. These alternatives include small-scale strategies such selling tourism related items or lottery tickets, and a large-scale strategy that includes developing a commercialized rest area outside of the interstate right of way through a public-private partnership. In addition, CDOT could advocate for changes to federal law.
This report develops a framework for organizing risk-based decisions about design, maintenance, and operation for the Colorado Department of Transportation (CDOT) applying to various types of facilities. It also provides illustrative examples for the use of the proposed framework. CDOT has an opportunity to be a national leader in assessing risks, vulnerabilities, consequences and outcomes through the implementation of a risk-based framework for facility design, operations and maintenance.
Thermal Mapping surveys were carried out on approximately 1000 miles of the Colorado Department of Transportations (CDOTs) roads. The purpose of these surveys was to identify road surface variations across the network to determine whether forecast Thermal Maps or the data from the surveys would be useful to decision-makers in the CDOT regions.
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 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.
This study evaluates the strength and long-term performance of CFRP prestressed panels in a bridge deck, compare the behavior of bridge decks designed with the empirical and conventional methods of AASHTO, and a new limit-state design, and examinne the influence of lap splices between precast panels on deck cracking.
