Motor Carrier Concerns About Transportation Problems In Oregon
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This report summarizes an analysis of data from a statewide survey of freight motor carrier firms, conducted by the Oregon Department of Transportation (ODOT) in the summer of 2001, to identify freight industry concerns about problems they encounter on Oregon’s roadways. The survey achieved a 61% response rate, yielding responses from 1,872 firms out of a sample of 3,064. Of respondents who said they encountered problems, about half mentioned concerns related to roadway infrastructure (such as pavement conditions, bridge problems, sharp curves, intersections or lane configurations). About 86% mentioned a variety of non-infrastructure issues. In this follow-up analysis of non-infrastructure problems, several specific topics of interest to the ODOT Motor Carrier Transportation Division were examined: weight enforcement, vehicle inspections, weight, length and height permits and restrictions; safety concerns; roadway speeds and speed limits; taxes on trucking; and roadway construction zones.
Concerns about weight, height and length restrictions and enforcement tended to be somewhat evenly divided between trucking firms who see the restrictions themselves as a problem and those who have concerns about weigh stations and enforcement. Safety concerns tended to center around roadway physical conditions and configuration, and the behavior of other drivers. Truckers’ concerns about speeds focused on the difference in posted speeds for autos versus trucks and the view that truck speeds should be increased. Taxes were cited as a problem by about 6% of those who identified problems. Among those who had concerns about construction zones, delays were a primary concern.
Truck Trip Data Collection Methods
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A considerable body of research exists for addressing the data needs for passenger transportation models and statewide freight truck movements. The number of studies which focus on methods for capturing the necessary data on urban freight movements is less abundant. This study addresses this problem by identifying those freight data attributes necessary for both urban region truck modeling and freight planning efforts and evaluates alternative data collection methodologies for providing these necessary data attributes. Data attributes such as origin-destination detail, route identification, land-use at stops, commodity, weight, vehicle configuration, time of day, volume of shipments and location of trip generators were identified as necessary for modeling and planning needs. Two pilot studies were conducted in the Portland, OR metropolitan area, to test truck trip data collection methodologies. One pilot study tested a roadside intercept survey method at three different locations, including an interstate highway weigh station, a Port of Portland marine terminal, and a private freight warehouse/distribution center. The other pilot study tested a combination of mail and fax survey methods used with two different sample types. The survey methods tested included straight mail, phone-mail, phone-mail-phone, straight fax, phone-fax, phone-fax-phone, sent to a “Known” and “Unknown” mail population. The results from the different freight data collection methodologies are presented and evaluated.
Permanent Deformation Characteristics of Oregon Mixes Using the Asphalt Pavement Analyzer
The Asphalt Pavement Analyzer (APA) device was used to characterize the impacts of various mix factors on the development of permanent deformation dense-graded mixes. Factors investigated included: aggregate size of 12.5 and 19 mm (0.5 and 0.75 in), VMA (high, design, low), fines content (design and high), binder content (low, design, high) and binder type (PG 64-22, PG 70-22, PG 76-22). A single aggregate source was used for all mixes. A compactive effort of 100 gyrations was used for all test specimens and specimens were tested at 64°C (147.2°F) following standard APA test protocol.
The measured rut depth did not exceed the NCAT recommendation of 8 mm (0.312 in) for any of the mixes tested. An increase in the binder content increased the permanent deformation of the mixes prepared with the PG 64-22 binder, irrespective of the other mix parameters. These effects were not noted in the mixes prepared with PG 70-22 and PG 76-22 binders, perhaps due to the standard test temperature of 64°C (147.2°F). All mixes prepared with the higher temperature binders showed very low permanent deformation when tested at the standard 64°C (147.2°F) regardless of the value of the older mix parameters.
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Evaluation of Intrusion Detection Technologies for High Speed Rail Grade Crossings
The rail industry is in the process of developing a prototype system for high speed rail. One of the concerns when using high speed rail is the danger of obstructions on the track. This level of danger is much higher than with traditional railway vehicles because the high speed passenger equipment is both lighter and faster moving than traditional equipment. It is therefore more vulnerable to serious damage and derailment by objects on the track.
The goal of this project was to evaluate methods for detection of objects on railway track where they are crossed by a roadway. Two existing traffic monitoring technologies were tested for their potential in railway intrusion detection: video and microwave.
Laboratory test results indicated that both systems appeared to have good potential for use in railroad intrusion detection. The video system was tested in indirect natural light, medium intensity artificial lighting and low level artificial lighting. Object detection was independent of color, composition, and direction of entry but was a direct function of detection zone size. Spheres as small as 4 inches (102 mm) in diameter, were consistently detected by the video system at distances of 15-25 feet (4.6-7.6 m). The microwave system consistently detected 4 inch (102 mm) spheres at the same distances, and results were independent of material, color, entry direction and zone size.
Field test results of both of the technologies were mixed. The video system was subject to detection problems during the day due to the much greater complexity of the field environment and at night due to light reflections from smooth surfaces. The microwave detection system reliably detected large objects such as automobiles, even in a complex field environment, but it did not reliably detect objects smaller than an auto. The ability of this system to detect smaller objects appeared to be severely compromised from confounding features such as metal objects that can reflect microwaves. The distance of objects from the detection unit may have also been a factor in its poor field performance.
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The study concluded that existing video and microwave-based traffic monitoring systems may have potential for use in a railroad intrusion detection application, but further refinement of the technologies is needed.
Shear Capacity Assessment of Corrosion-Damaged Reinforced Concrete Beams
This study investigated how the shear capacity of reinforced concrete bridge beams is affected by corrosion damage to the shear stirrups. It described the changes that occur in shear capacity and concrete cracking as shear stirrup corrosion progresses. Visual signs of corrosion distress were correlated with structural performance of large-size reinforced concrete beams that were corroded to four damage states. The corrosion products and damage were characterized for the beams and compared to field beams. Analysis methods incorporating quantified corrosion damage predicted reasonably well the shear capacity of the large-size beams. Recommendations were presented for improved inspection practice to allow for estimating shear capacity of corrosion-damaged sections in reinforced concrete bridges.
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The Effect of Law Enforcement Deployment Patterns on Motorists' Speeds
The combination of increased demands on Oregon’s transportation system and limited law enforcement resources has led the Oregon Department of Transportation (ODOT) to investigate whether a relationship exists between motorists’ speeds and law enforcement levels. If an optimum level of law enforcement could be identified that reduces the number of motorists driving in an unsafe manner, the end result could be a more efficient deployment of scarce law enforcement resources.
This study deployed enhanced law enforcement patrols at six study sites in Oregon to evaluate the effects of law enforcement presence on vehicle speeds. Investigators first recorded baseline speeds for a two-month period prior to the commencement of enhanced enforcement. Enhanced patrols varied from 10 to 25 hours per week on either fixed or random schedules. Enforcement at each site was on an eight-week cycle: two weeks of enhanced patrols followed by six weeks of normal patrols.
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The data analysis compared median and 85th percentile speeds in the baseline and enhanced enforcement conditions. Baseline and enhanced enforcement data were also compared for the percent of vehicles traveling over the posted speed at each site. The findings showed that enhanced patrols resulted in small but statistically significant reductions in speed at most of the test sites. Both median and 85th percentile speeds were significantly higher than posted speeds at all of the study sites in both the baseline and the enhanced enforcement conditions.
Evaluation of Oregon Department of Transportation Project Delivery - Literature Review & DOT Survey
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This report summarizes a review of literature regarding outsourcing by Departments of Transportation (DOT), with particular emphasis on outsourcing of project delivery, and on performance measures for project delivery. The report also summarizes information obtained from a brief e-mail survey of the 50 US DOTs, and a follow-up detailed questionnaire survey and telephone interviews. The information in this report lays the groundwork for comparative evaluation, over a three-year period, of projects delivered by the Oregon Department of Transportation using insourced design-bid-build, outsourced design-bid-build, and design-build. The results of this analysis and the proposed guidelines for selecting project delivery methods for specific projects will be included in the final report in 2006.
Washing Bridges to Reduce Chloride - Interim Report
Chloride ions are known to promote the corrosion of steel in reinforced concrete. This project was undertaken to investigate the efficacy of washing, to reduce chloride content and chloride ion uptake. The project consists of a laboratory and an field component over a period of four years.
In the field component test sections of a coastal bridge have been pressure washed on a once per year and twice per year schedule. A set of washing trails is also being conducted on concrete blocks exposed to salt water in the laboratory, to determine whether chloride ions can be removed from the concrete and whether the ingress of chloride ions can be reduced. After two years, the effects of washing on removing chloride ions was inconclusive, but washing did reduce the uptake of chloride ions by up to 89%. Chloride levels decreased with a washing cycle of once per day, but on change was observed with washing cycles of once per week or once per month.
Based on these results, field testing on the bridge was discontinued. The laboratory washing will continue for another two years.
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Concrete Patching Guide
Maintenance personnel often select a material for patching concrete based on what they have used in the past. However, each patching job has particular demands, which may be different from what was required in past applications. Also, the list of available products changes often with manufacturers producing new patching materials, discontinuing some products and changing the name of products.
The Oregon Department of Transportation recognized the difficulty in selecting the right patching material and developed a patching guide to help maintenance personnel determine which product to use. The selection tool is based on a Microsoft Excel spreadsheet and matches the attributes of specific products to the needs of a particular patching job. An output report is then generated and provides a list of qualified and conditional products from the QPL (Qualified Products List).
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Determining Asphalt Content for Recycled Asphalt Pavement (RAP) Materials
The State of Oregon uses significant amounts of Recycled Asphalt Pavement (RAP) in dense-graded mixes on State highways. The design process for these mixes relies on accurately knowing the amount of asphalt cement in the RAP materials being used. Beginning in 1997 ODOT began using ignition furnaces to determine RAP asphalt contents and gradations.
Asphalt contents are determined by measuring the change in mass between the original dry RAP sample and the mass of the final residue aggregate sample after the asphalt is burned off in the ignition furnace. One shortcoming of the process is that a small portion of the aggregate is usually lost in the burning process. The amount of aggregate lost is on the order of 0.5% which may be considered significant for most RAP mixtures.
This research attempted to use volumetric equations to solve for the RAP asphalt content by exploiting the constant nature of the Effective Specific Gravity of Aggregates, Gse. A solution is presented using a simplified equation which ignores the difference in Specific Gravity of Asphalt, Gb, between the RAP asphalt and the new added asphalt. This solution proved to be unstable and diverged significantly with only small changes in assumed Gb.
A second more exact equation was derived to better account for the difference in Gb between the RAP asphalt and the new added asphalt. However, it’s analytic solution collapsed to zero due to the dependent nature of the volumetric equation being used. Attempts to derive a second linearly independent equation failed; however, future research may lead to a complete solution to this equation.
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Maturity Method Demonstration
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The concrete maturity method is a quality control/quality assurance tool that can be used to assist contractors and transportation officials in producing cost-efficient, durable concrete structures. This report documents the findings of an investigation performed for the Oregon Department of Transportation to demonstrate the use and benefits of the maturity method. The maturity method was shown to be an easily implemented QC/QA tool that can be used to estimate strength development, speed construction operations, and document contractor mistakes.
Development and Evaluation of Fiber Optic Sensors
This study investigated the feasibility of using fiber optic sensors to capture traffic data. Funding from the study was used to develop a prototype sensor using fiber Bragg gratings (FBG) technology. The sensor was tested on a high volume Portland cement concrete highway and found to be feasible for use in monitoring light and heave traffic. Signals from the sensor were processed with a demodulator system, and captured on a computer. For testing purposes, the signal was converted to a scaled analog voltage signal and successfully output to a conventional traffic classifier recorder.
The sensors have the potential for long-lasting, cost-effective solutions in vehicle classification applications. With modification, the FBG strain sensor shows potential for use in weigh-in-motion applications.
The system is sensitive enough to detect adjacent lane traffic, opening possibilities of shoulder area monitoring for less traffic disruption and increased safety. With two sensors, the system can capture speeds as well as weights of both sides of a vehicle.
Future development of dedicated demodulator/interfacing electronic hardware and auto-tuning grating system could eventually lead to cost effective solutions for traffic classification and weigh-in-motion applications.
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Nighttime Construction and Maintenance
Selection Criteria for using Nighttime Construction and Maintenance Operations
Like other state departments of transportation, the Oregon Department of Transportation (ODOT) has emphasized preservation of existing highways and bridges. Thus, ODOT has done construction and maintenance work at night in order to minimize the disruption of daytime traffic. However, nighttime operations produce a new set of concerns such as safety, public relations, productivity, and quality. Decision-making for using nighttime operations in Oregon has been subjective and has relied on judgment without the benefit of analytical data and evaluation criteria. Therefore, a decision model that facilitates the determination of when to use nighttime road construction and maintenance work was developed. From the literature review, 19 factors affecting decision-making were identified and used to create a survey. The investigators surveyed ODOT personnel, ODOT’s contractors, and the representative personnel from other departments of transportation. After analyses of various perspectives, the overall result was fairly consistent with the results from the individual respondent groups. The results provided the ability to eliminate unimportant factors, determine weights of important factors, and build a decision model to improve the effectiveness of decision-making. The decision model was tested by applying it to actual ODOT projects and comparing its recommendations on when to conduct the projects with actual decision makers’ decisions. The overall testing results were consistent with current decision makers’ subjective decisions because of the impact of congestion within the decision model. The decision model in this study provides a practical and useful tool to help decision makers in real work environments analyze when to use nighttime work. The model will be useful for making decisions consistently and provides a means to explain the decision to the stakeholders.
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Effects of Bromacil, Diuron, Glyphosate, & Sulfometuromethyl on Periphyton Assemblages & Rainbow Trout
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This study documents the testing of several common herbicides used by the Oregon Department of Transportation in vegetation management. The project assessed the short-and long term effects of Roundup, Krovar and Oust on periphyton and rainbow trout. The active ingredient in roundup is glyphosate; Krovar uses bromacil and diuron; and Oust used sulfometuron-methyl. Short-term (96 hour) exposure test used actual road shoulder runoff collected after herbicide application, using a simulated rain and a natural rain event. Long-term exposure test assessed effects of a 14-day exposure using lab-mixed solutions of deionized lab water and herbicides, individually and in mixture.
The data showed that the short-term exposure had no statistically significant effects on periphyton. The short-term exposure reduced survivorship of rainbow trout, but the effects were observed both in treated and untreated runoff; thus the toxicity was likely due to other factors.
The long-term exposure test showed that herbicides, especially Krovar and the mixture of three chemicals, reduced periphyton algal biomass. The declined trend in biomass was more evident in live cell density than in chlorophyll a concentration, suggesting that algal responses to chemicals may vary among groups (green algae vs.. diatoms). The long-term exposure had no statistically significant effects on fish mortality and dry weight. Individual herbicide bioassays showed no significant differences between the changes in wet weight, but significant differences in wet weight, the effect on other sublethal endpoints remains a possibility.
Field Trial of Solvent-Free Emulsion
This final report summarizes construction, laboratory and performance information gathered by ODOT personnel from a single field trial of solvent-free emulsion mix constructed in June 2001. The solvent-free emulsion mix presented several placement problems as it built up on the laydown screed and gouged the mat. A second project trial section, scheduled for construction during 2001, was not completed due to construction scheduling problems.
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Following standard ODOT design policy, both the solvent-free and conventional emulsion mixes were overlaid with a chip seal shortly after placement. After fourteen months, the performance of both mixes appeared.
Effectiveness of Double Fines as a Speed Control Measure in Safety Corridors
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The use of elevated traffic fines, and specifically doubling of applicable traffic fines under certain conditions, is widely used in Oregon as a speed control measure. Double fines have applied to “safety corridors” in Oregon since 1999. Double fine signing in safety corridors has been used on a trial basis in two locations. While safety advocates promote the use of signing to alert drivers of double fines, there has been little if any compelling evidence produced to date that it is effective in crash reduction. This research effort is based on a telephone survey of 651 adult Oregon drivers, who were asked about their decision to speed in a variety of different situations, to determine whether their judgments differed from one situation to another. The results were used to infer indirectly whether double fine signing was influencing their judgments. The analysis of the survey results showed that when considering safety corridors, people do not report the same elevated perception of crash risk that they report for work zones and school zones. They also do not have the same elevated perception of citation or fine risk. If it is recommended that double fine signing in safety corridors be retained, the report concludes that other countermeasure enhancements should also be considered to achieve more effective speed control in safety corridors.
Technology Evaluation for Implementation of VMT Based Revenue Collection Systems
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The Road User Fee Task Force (RUFTF) was created as part of House Bill 3946 with the purpose of developing a new revenue collection system design for Oregon’s roads and highways. The Oregon Department of Transportation (ODOT) is required by House Bill 3946 to begin implementation of pilot alternative revenue collection systems by July 1, 2003. One alternative being considered by the RUFTF is a Vehicles Miles Traveled (VMT) based fee. Currently, ODOT has limited technical information relative to the technologies available that could potentially be used to implement an electronic revenue collection system based on the VMT principle. The research performed in this project focused on obtaining and synthesizing such technical information for ODOT. Technologies explored include, but were not limited to, GPS-based devices, Radio-Frequency Automatic Vehicle Identification devices, and different means of electronic data transfer. This information is then used to assess the feasibility (both technical and economic) of various electronic revenue collection system concepts and to identify technological needs. Based on the results, several conclusions and recommendations are presented.
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Reducing Seismic Risk to Highway Mobility: Assessment and Design for Pile Foundations Affected by Lateral Loading
Damage in pile supported structures due to liquefaction and liquefaction induced deformation were reported in past earthquakes around the world (eg, Ansal et al. 1999; Seed et al. 1990; EERI 2010, EERI 2011; GEER 2010a, GEER 2010b, GEER 2011). For example, a reconnaissance report from a recent subduction zone event, the 2010 Chile earthquake (Mw=8.8), showed the pervasive nature of liquefaction and liquefaction-induced lateral spreading damage to bridge foundations (GEER 2010a, Yen et al. 2011). In terms of seismic hazard, the Pacific Northwest shares similar conditions from a Cascadia Subduction Zone (CSZ) earthquake source with the expected earthquake magnitude of 9.0 (Mw) and return period of 300 years (Atwater et al. 1995, Atwater and Hemphill-Halley 1997). The risk and damage from a CSZ earthquake event is widely recognized by the Oregon Department of Transportation (ODOT) as presented in a report by ODOT (2009). A large number of bridges were found to be vulnerable to a CSZ event, and repair and replacement costs of Oregon bridges have been estimated at more than 1 billion USD (ODOT 2009). Moreover, thousands of bridges require some kind of modification and/or seismic retrofitting to the foundation in order to improve seismic performance under liquefaction induced lateral spreading.
To evaluate the seismic performance of bridge foundations and liquefaction mitigation alternatives, ODOT/OTREC funded collaborative research between Oregon State University (OSU), University of California at Davis (UCD), University of California at San Diego (UCSD), Hayward Baker Inc., and Pacific Earthquake Engineering Research Center (PEER). The main objectives of the research were to develop design charts for different liquefaction mitigation alternatives and to develop methodologies for assessing the performance of bridge pile foundations in laterally spreading ground.
The cooperative research focuses on two aspects of liquefaction and liquefaction induced lateral spreading: (1) ground improvement methods, particularly using stone columns and deep soil mixing (DSM) grids, and (2) assess the seismic performance of bridge foundations (e.g., drilled shaft, pile groups) and seismic retrofitting alternatives for the bridge foundation. Stone columns for liquefaction mitigation and pile groups foundation assessment were investigated by the OSU team, while DSM and large diameter piles/shafts alternatives were investigated by the UCD team. Research teams used OpenSees (http://opensees.berkeley.edu/
), an open source computational platform for three dimensional (3D) finite element (FE) modeling and analysis. OpenSeesPL, a graphical user interface developed by the UCSD team, was used to investigate liquefaction mitigation alternatives (i.e., stone columns and DSM grids) and the performance of pile foundations in liquefaction induced laterally spreading ground.