Oregon Department Of Transportation Research Articles

Underwater sound from rotary oscillator and pile driving construction activities - I-205 Bridge over the Willamette River - I-205 Abernethy Bridge, Oregon

The Oregon Department of Transportation (ODOT) is conducting construction work in the Willamette River that involved the installation of piles through the water. There is a potential for impacts to wildlife, primarily fish, due to high noise levels. The project added piers to the existing bridge that consist of 12-foot diameter pile casings and drilled shafts. These casings are installed through rotary-oscillation drilled shafts that extended well below the water. These piles extend 200 feet below the river bottom. A large rotary oscillator was required to install the casings, which was supported on temporary platforms constructed in water. The platforms were supported by hollow 36-inch diameter steel piles. Underwater sounds from rotary oscillators have not been measured extensively in the past. This paper describes the underwater sound levels and characteristics of drilling large diameter casings deep through the substrate using the rotary oscillator. Measurements were also conducted for impact pile driving sounds from installation of the 36-inch diameter piles. The sound measurements evaluated the effectiveness of air bubble curtains meant to reduce sound from impact pile driving and meet permit requirements to minimize exposure of fish to harmful sound levels.

Economic and Operational Impacts of Three-Dimensional Engineered Models and Automated Machine Guidance on Statewide Roadway Projects

This paper investigates the economic and operational impacts of two advanced technology initiatives at the Oregon Department of Transportation (ODOT). A three-dimensional (3D) engineered model (3D-EM) and automated machine guidance (AMG) are the results of the agency’s push to take existing 3D design software and create fully detailed 3D computer models for all applicable projects, leading the way for AMG to reach a highly accurate on-the-ground implementation of the project design. Following a case study approach, this paper presents a method to quantify the costs and benefits of this endeavor using return on investment (ROI) and benefit/cost (B/C) ratio, and a method to estimate the odds of PASS (success) for a grade verification point (GVP) using odds and odds ratio. The ROI showed a return of around $23 for every $1 invested in enabling 3D-EMs creation and thus facilitating AMG use on projects for the period from 2014 to 2016. The odds and odds ratio showed that AMG-equipped machines are much more accurate than traditional machines depending on Stakes. The odds of PASS for a GVP in AMG projects are estimated to be 416 times the odds of PASS for a GVP in Stakes projects. The primary contribution of this paper is that it shows how the two investigated technologies, especially when working together, positively impact a state DOT (in this case ODOT) economically and operationally throughout the construction phase of projects.

Determining the Optimum Sample Size for Quality Assurance (QA) of Asphalt Mixtures: A Case Study

Acceptance plans for asphalt mixtures use a certain sample size that is often established based on the purpose of sampling, population size, risk, and allowable error for evaluation. The rate of quality control (QC) sample size is often higher than the quality assurance (QA) sample size. The test results obtained from the QA samples are commonly used to validate the QC test results and to assist the state department of transportation (DOT) with payment decisions. However, if the QA sample size is insufficient to make accurate judgments, the probability of making incorrect decisions regarding acceptance increases. On the other hand, oversampling needlessly consumes both time and cost. To identify the appropriate sample size for QA testing, a balance must be struck between a number of variables. In this case study, two models were developed using the Oregon Department of Transportation (ODOT) data to determine the appropriate QA sample size. The need for this work was realized when a review of ODOT paving projects revealed a large variability in lot size. These ranged from 3000 to more than 100 000 tons with commensurate QA sample size rates. The typical standard deviation (STDEV) values of asphalt content (AC) and in-place density were determined. The developed models show that using the STDEV values that represented more than 90 percent of the projects, ODOT needed to increase QA sample size for both AC and density in lots of less than 22 000 tons. The results also show that sample can be decreased for AC and remain as is for density in projects of more than 22 000 tons of asphalt mixtures. The proposed models can be used to determine the optimum sample size for different lots sizes.

Case Study: Economic Analysis of Statewide Roadway 3D Mapping Using Mobile LiDAR

AbstractThe Oregon Department of Transportation (ODOT) has been using survey-grade mobile Light Detection and Ranging (LiDAR) technology to scan and create three-dimensional (3D) representations of...

Impermeable Asphalt Concrete Layer to Protect and Seal Concrete Bridge Decks

Deterioration of the concrete bridge deck is one of the most significant problems affecting the service life of bridges in the United States (U.S.). The early failure of asphalt pavement overlays on concrete bridge decks with spray-on waterproofing membranes has been recognized as a significant issue by the Oregon Department of Transportation (ODOT). Potential reasons for the failure of the asphalt overlays were thought to be the poor adhesion between the waterproofing membrane and the asphalt-wearing course, and the material properties of the asphalt layer. Moisture penetration into the asphalt overlay and standing water on the concrete bridge deck result in expansion and contraction at the interface on the bridge deck during freeze-thaw cycles. Expansion and contraction because of freeze-thaw cycles cause debonding at the interface and result in an increased rate of deterioration for the asphalt concrete overlay. Additionally, the de-icing salts used to prevent hazardous roadway surfaces in the winter permeate into the deck and cause corrosion of the steel reinforcement, weakening the structural integrity of the bridge. The main goal of this study is to develop an impermeable asphalt mixture with high cracking and rutting resistance that can seal and protect the concrete bridge deck by preventing water and de-icing salts from penetrating into the concrete deck. Permeability of developed asphalt mixtures was quantified by permeability testing and moisture sensor measurements. Rutting and cracking resistance of the developed impermeable asphalt mixture strategies were also evaluated by conducting flow number (FN) and semi-circular bend (SCB) tests in the laboratory.

Preliminary Local Calibration of Performance Prediction Models in AASHTOWare Pavement ME Design for Flexible Pavement Rehabilitation in Oregon

AbstractThe Oregon Department of Transportation (ODOT) is in the process of implementing the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) for new pavement sections. However, the vast ...

Assessing Roadway Contributions to Stormwater Flows, Concentrations, and Loads with the StreamStats Application

The Oregon Department of Transportation (ODOT) and other state departments of transportation need quantitative information about the percentages of different land cover categories above any given stream crossing in the state to assess and address roadway contributions to water-quality impairments and resulting total maximum daily loads. The U.S. Geological Survey, in cooperation with ODOT and the FHWA, added roadway and land cover information to the online StreamStats application to facilitate analysis of stormwater runoff contributions from different land covers. Analysis of 25 delineated basins with drainage areas of about 100 mi2 indicates the diversity of land covers in the Willamette Valley, Oregon. On average, agricultural, developed, and undeveloped land covers comprise 15%, 2.3%, and 82% of these basin areas. On average, these basins contained about 10 mi of state highways and 222 mi of non-state roads. The Stochastic Empirical Loading and Dilution Model was used with available water-quality data to simulate long-term yields of total phosphorus from highways, non-highway roadways, and agricultural, developed, and undeveloped areas. These yields were applied to land cover areas obtained from StreamStats for the Willamette River above Wilsonville, Oregon. This analysis indicated that highway yields were larger than yields from other land covers because highway runoff concentrations were higher than other land covers and the highway is fully impervious. However, the total highway area was a fraction of the other land covers. Accordingly, highway runoff mitigation measures can be effective for managing water quality locally, they may have limited effect on achieving basin-wide stormwater reduction goals.

Rough Roads Ahead 2: Economic Implications of Deteriorating Highway Conditions

This study presents a high-level, strategic assessment of the long-range implications of Oregon’s current forecast budget for highways. The current highway budget is insufficient to meet current state goals with respect to transportation system condition, requiring the Oregon Department of Transportation (ODOT) to prepare for strategic investment decisions. ODOT must conceive new ways to develop the most efficient use and management of facilities while accepting lower performance standards, shifted use of deteriorating facilities, and the need to allocate resources to priority locations.The Oregon Statewide Integrated Model was used to evaluate three hypothetical scenarios over a 20-year period, representing investment strategies implemented with budget increases and compared with the current 20-year forecast budget. The purpose of the analysis was to evaluate the potential impact of highway disinvestment on Oregon’s economic competitiveness. The primary focus was on bridges, as over half of Oregon’s bridges are nearing the end of their life cycle. Weight-restricted bridges significantly impact the cost of moving freight in Oregon, where over 70% of freight moves by truck. In addition, registered passenger vehicle records were used to estimate the impacts of deteriorating pavement conditions on Oregon highway users.

A study of top-down cracking in the state of Oregon

A major concern from the Oregon Department of Transportation (ODOT) in recent years has been the prevention of top-down cracking in HMA pavements shortly into their design lives. To this end, the ODOT has identified hot mix asphalt (HMA) pavements that have displayed top-down cracking within three years of construction for evaluation. This study’s main objective is the evaluation of top-down cracked pavement sections against results collected from non-cracked pavement sections, and the identification of practices that will prevent top-down cracking from occurring. Six surface cracked pavements and four non-cracked pavement sections were used for conducting this research. Extensive field and laboratory investigations were done through distress surveys, falling weight deflectometer testing, dynamic cone penetrometer (DCP) testing, coring from cracked and non-cracked pavement sections, and testing of cores for HMA mixture rheology and asphalt binder rheology. The laboratory investigation included dynamic modulus, indirect tensile strength, and specific gravity testing on the HMA cores, rheological tests on asphalt binder and aggregate gradation analysis. Results suggest that prevention of top-down cracking can be improved through tighter control on density (air void requirements) and asphalt binder selection during material selection and initial construction.

Urban Transportation Mode Choice and Trip Complexity: Bicyclists Stick to Their Gears

The benefits of public policies designed to alleviate traffic congestion, reduce pollution, and improve public health rest heavily on the value that commuters place on time and how they make transportation mode decisions. However, over the last several years, commuter lives have become more complicated with rising income. This has impacted transportation decisions. In my model, transportation mode choices are made simultaneously with the choice of whether or not to make multiple stops (termed travel complexity). Unlike other studies, I account for commuters' unobserved preferences for particular transportation modes. Using travel behavior data collected by the Oregon Department of Transportation, I estimate the model using an error components logit (ECL) specification and find that not allowing for unobserved commuter preferences for particular transportation modes underestimates value of travel time (VOT) and over-predicts complex trip choice relative to the crossing-components ECL. The estimated model predicts that increased trip complexity causes substitution away from public transit to automobiles, with the exception that bicyclists transition only to more complex trips and do not change transportation modes.

Evaluation of Beginner Driver Education in Oregon

Although driver education (DE) is widely accepted as an effective teen driver safety measure and widely available in the United States, Canada and elsewhere, evaluations have generally failed to show that such formal programs actually produce safer drivers. To address the issue of safety effects as part of a larger investigation, two studies were conducted to examine whether the Oregon Department of Transportation (ODOT)-approved DE program was associated with reductions in collisions and convictions. In the first study, DE status among a relatively small sample of teens who completed an online survey was not found to have a significant effect on collisions and convictions. In the second study, of a much larger population of teen drivers, DE status was associated with a lower incidence of collisions and convictions. On balance, this suggests that the safety effects of DE are either neutral, based on the results of the first Oregon study, or cautiously optimistic based on the results of the second study. The implications of these findings are discussed in terms of making improvements in DE that are evidence-based, and the need for further evaluation to establish that improved and new programs meet their safety objectives.

Preparing Oregon for Connected Vehicle Deployment: Application Prioritization Process

To build on a project recently completed for the Oregon Department of Transportation (DOT), processes and tools were developed to prioritize the implementation of connected vehicle (CV) applications. Internal mechanisms for addressing CV development and deployment at the Oregon DOT were assessed; the technical maturity of each potential CV application was scanned, reviewed, and assessed; preliminary goals were developed; prospective CV applications were linked; and applications that fit with the potential role of the Oregon DOT in advancing these initiatives were refined, prioritized, and ranked. A shared vision and business plan that prioritizes CV applications for Oregon is recommended. An internal effort aimed at producing a small set of priority CV applications for further development is described. This effort culminated in a CV application prioritization workshop that included a priority mapping exercise, discussion of the CV concept, and an initial mapping of goals and applications. The workshop identified seven near-term priority CV applications for the Oregon DOT; 12 applications that the Oregon DOT will monitor (and possibly collaborate on with others in the future); and eight applications that the Oregon DOT will monitor but that will be led by others. The Oregon DOT has used the results of this effort as a springboard for hiring new staff dedicated to CV policy, forming a CV steering team, and launching a CV business plan. The process and tools can be used by other states and transportation agencies in their CV application prioritization processes.

Assessing State Department of Transportation Readiness for Connected Vehicle–Cooperative Systems Deployment: Oregon Case Study

As connected vehicle (CV) research moves into deployment, metropolitan planning organizations; state, local, and transit agencies; and the private sector will start experiencing the effects of vehicles, aftermarket devices, mobile devices, and infrastructure with dedicated short-range wireless communications and other wireless connectivity at their cores. Like other states and regions, the Oregon Department of Transportation (DOT) could benefit from the preliminary scoping, evaluation, and assessment of the impact of CVs and infrastructure and a wide range of potential cooperative system applications. With this in mind, the Oregon DOT is determining whether to pursue the next phases of federal funding for CV applications. The Oregon DOT also wants to make an informed choice about taking a national leadership role in the CV arena and to assess opportunities to join projects with other partners. This paper describes the empirical results of a survey that, to assist the Oregon DOT in its assessment, was distributed to agency staff to gauge the perception of CV and automated vehicle (AV) technology. Most respondents had heard of this technology and were in favor of its application. However, many respondents had concerns about cybersecurity and the catastrophic consequences of system failure, and many respondents voiced concerns about the Oregon DOT’s preparedness for CVs or AVs. The Oregon DOT and other agencies can use these findings to help prepare for a better future with CVs and AVs.

Preparing a Roadmap for Connected Vehicle/Cooperative Systems Deployment Scenarios: Case Study of the State of Oregon, USA

Safety remains a problem on U.S. roadways, with more than 32,000 fatalities, 2.2 million injuries and 6 million crashes each year. Travelers, shippers and the economy are exposed to increasing amounts of congestion, unreliability, delay, emissions and excess energy consumption, which impede the efficient movement of people and goods. The U.S. Department of Transportation (DOT) had embarked upon a major research program toward implementing connected vehicle safety technologies, applications and systems using dedicated, short-range wireless communications (DSRC). Previous research by the National Highway Traffic Safety Administration (NHTSA) demonstrated that 80% of unimpaired driver crash types could be addressed by the connected vehicle technology.Through the year-long Safety Pilot that took place in Michigan from 2012 to 2013, U.S. DOT tested the effectiveness of wireless connected vehicle technology in real-world, multimodal driving conditions; collecting data about how ordinary drivers adapt to the use of connected vehicle technology; and identifying the potential safety benefits of connected vehicle technology. This work was performed in recognition of a February 3, 2014 NHTSA agency decision for light vehicles and a similar decision expected soon for commercial vehicles that will likely launch regulatory processes to require or incentivize all new vehicles to be equipped with DSRC devices. Communication among and between vehicles and the infrastructure (including traffic signals, work zone equipment, or pavement sensors, and other infrastructure elements) would also have data and mobility benefits (including data-driven applications such as traveler information for freight and passengers, transit operations, network flow optimization, traffic signal systems and incident response, emergency staging, and evacuation as well as sustainability-related applications).This paper describes an ongoing effort to explore opportunities for the state of Oregon, USA, to participate in future funded pilot deployments of mobility and environmental related applications in the coming years—possibly including a set of regional pilots as well as smaller, more self-contained projects focused on priority applications. As connected vehicle research moves into deployment, state, local and transit agencies, Metropolitan Planning Organizations and the private sector will start experiencing the effects of vehicles, after-market devices, mobile devices, and infrastructure with DSRC and other wireless connectivity at their cores. Along with other states and regions, the Oregon Department of Transportation (ODOT) can benefit from preliminary scoping, evaluation, and assessment of the impact of connected vehicles and infrastructure and a wide range of potential cooperative system applications. With this in mind, ODOT can determine whether or not to pursue the next phases of federal connected vehicle application funding. It can also make an informed choice about taking a potential national leadership role in the connected vehicle arena, and assess opportunities to join projects with other partners. This paper provides a summary of an internal survey conducted within ODOT along with insights gained from the analysis of the survey results. Next steps in the process are also described.

Oregon’s All Roads Transportation Safety Program: Data-Driven Program to Improve Safety on All Public Roads

Historically, the Oregon Department of Transportation (DOT) has spent the Highway Safety Improvement Program (HSIP) funding only on state highways. However, half of the fatalities and serious injuries occur on nonstate roadways. To address this concern and to comply with the federal requirement that the HSIP funding be spent on all public roads, the Oregon DOT developed a jurisdictionally blind safety program, known as the All Roads Transportation Safety (ARTS) Program, to address safety problems on all public roads in Oregon. The objective of the ARTS Program is the same as that of the HSIP: to reduce fatalities and serious injuries on all public roads using a data-driven approach. The ARTS Program has two components: hot spot and systemic. For the first round of the ARTS Program, safety projects were selected by using a combination of a selection approach and an application-based approach. For the hot spot component, potential safety projects were identified by using crash history, and the projects were prioritized on the basis of benefit–cost ratios. The systemic component—with three emphasis areas: roadway departure, intersection, and pedestrian and bicycle—was an application-based process in which the Oregon DOT and local agencies competed for available safety funding. Systemic projects were prioritized on the basis either of benefit–cost ratios (roadway departure and intersection projects) or cost-effectiveness index (pedestrian and bicycle projects). Through collaboration with various stakeholders, the Oregon DOT was able to select safety projects on all public roads with a data-driven approach. It is expected that these projects will significantly improve safety on all Oregon roads by reducing fatal and serious injury crashes.

Accuracy of Bicycle Counting with Pneumatic Tubes in Oregon

Interest in counting bicycles and establishing nonmotorized counting programs is increasing, but jurisdictions still struggle with how to integrate bicycle counting into standard practice. In this paper, the authors share findings and recommendations for how to minimize error for bicycle counting from tests conducted in conjunction with the Oregon Department of Transportation. This research studied three types of off-the-shelf pneumatic tube counters for counting bicycles, including equipment from five manufacturers: two bicycle-specific counters, three varieties of motor vehicle classification counters, and one volume-only motor vehicle counter. Tests were conducted both in a controlled environment and in on-road mixed traffic to better identify problems in accuracy. Equipment studied generally undercounted cyclists, especially those in groups. Results from the controlled test with standard bicycles showed that within 10 ft of the counter, the undercounting error ranged from 0% to −12%. In the mixed-traffic test, all the equipment tested tended to undercount with mean percent error ranging from −10% to −73%. Each counter type has pros and cons, but in general, counting accuracy decreased with increases in bicycle and motor vehicle traffic and longer tube lengths. Higher accuracy can be achieved by careful selection of equipment type, classification scheme, and tube configuration. Bicycle speeds given by off-the-shelf pneumatic counting equipment were accurate.

Maximizing Statewide Multimodal Transportation Systems: Looking to Transportation Option Solutions in Oregon

In an era of limited and constrained funding, transportation agencies struggle to meet the needs of travelers and the demands on the system. Agencies need creative and low-cost transportation solutions and seek to identify ways to maximize use of existing multimodal networks. As a result, Oregon has recognized the role that transportation demand management strategies and transportation options can play in spreading demand across modes, enhancing interest in multimodal options, and facilitating connections between modes. In 2015, the Oregon Department of Transportation, with broad stakeholder input and support, produced the state’s first Transportation Options Plan. The plan defines transportation solutions, includes justification for their application, and charts a path forward for the state to realize operational and efficiency gains on the transportation system, and for the state to experience economic, public health, and other benefits as a result of these investments. This paper summarizes a statewide approach to investing and implementing transportation options solutions and highlights the benefits that can be achieved.

Evaluation of Signalized-Intersection Crash Screening Methods Based on Distance from Intersection

A probability sample of signalized intersections was collected from Oregon to review the performance of various strategies for identifying intersection-related crashes. Data from 73 intersections were collected with satellite imagery and databases from the Oregon Department of Transportation. Crashes from 2010 to 2012 were identified and manually classified as either intersection-related or not on the basis of geolocation, field codes in the crash databases, and geometric characteristics. This evaluation identified two sets of crashes: one with 964 intersection-related and another with 571 non-intersection-related crashes. The authors then studied how the probability of a crash's being intersection-related changes with the distance to the intersection and other relevant variables. Statistical model development used 55 intersections; the remaining 18 were left for comparison of various classification methods. Findings of this comparison were confirmed with data from all 73 intersections. Results indicated that regression models yielded results comparable with those from simpler methods based on distance only. The popular method of selecting crashes that are within a 250-ft radius tends to identify fewer intersection-related crashes than actually exist. A threshold of 250 ft, therefore, would result in underprediction of intersection crashes when safety performance functions are developed. This research found that a threshold of 300 ft potentially minimized such a risk of underestimation; however, using 250 ft might still be appropriate if minimizing the frequency of false positive identifications was of interest.

Evolution and Usage of the Portal Data Archive

The Portal transportation data archive ( http://portal.its.pdx.edu/ ) was begun in June 2004 in collaboration with the Oregon Department of Transportation, with a single data source: freeway loop detector data. In 10 years, Portal has grown to contain approximately 3 TB of transportation-related data from a wide variety of systems and sources, including freeway data, arterial signal data, travel times from Bluetooth detection systems, transit data, and bicycle count data. Over its 10-year existence, Portal has expanded both in the type of data that it receives and in the geographic regions from which it gets data. This paper discusses the evolution of Portal. The paper describes the new data, new regions, and new systems that have been added and how those changes have affected the archive. The paper concludes with a section on the uses of Portal that provides several examples of how Portal data have been used by regional partners, with a focus on measuring the performance of the multimodal transportation system, but also including educational elements and research.

Oregon Statewide Transportation Strategy

Challenged by the state legislature to find a way of reducing greenhouse gas (GHG) emissions substantially, the Oregon Department of Transportation embarked on a 2-year effort to determine the best strategies for reducing transportation-related emissions. The resulting Statewide Transportation Strategy: A 2050 Vision for Greenhouse Gas Emissions Reduction (STS) was accepted by Oregon's Transportation Commission in early 2013. The report charts a potential path forward to help meet Oregon's 2050 goal of a 75% reduction in GHG emissions compared with 1990. The STS development process was inventive and rigorous. A new policy-level analysis model, GreenSTEP, was created and was enhanced throughout the effort; GreenSTEP is being used by several metropolitan areas throughout the state and has been adapted nationally. During the development of the STS, analytical and political hurdles were overcome and lessons were learned. Some of those lessons are described in this paper, and a methodological approach is offered for others to follow.