Maximizing Investments in Work Zone Safety in Oregon
Due to the federal stimulus program and the 2009 Jobs and Transportation Act, the Oregon Department of Transportation (ODOT) anticipates that a large increase in highway construction will occur. There is the expectation that, since transportation safety grant funds may not increase and due to the lack of police enforcement resources, ODOT will need to be more strategic in planning how the available funds will be used. Questions regarding the allocation of safety grants among enforcement, equipment, and public education, and the optimal use of funds within each category, are being asked.
Thus, a research project was initiated to investigate methods for maximizing work zone safety investments. The goal of this research project is to:
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• provide guidance for maximizing ODOT’s investments in work zone enforcement;
• determine if additional coordination between the work zone enforcement program and the traffic control planning and work zone management efforts would enhance the programs; and
• review the effectiveness of the work zone safety public education program both in terms of message and media and determine if other approaches should be considered.
Copper Speciation in Highway Stormwater Runoff Related To Bioavailability & Toxicity to ESA-Listed Salmon
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The objectives of this study were to 1) identify the effects of site location, storm hydrology, and water quality parameters on the concentration of dissolved copper (Cu2+diss) in Oregon highway runoff; 2) establish an analytical technique suitable for the determination of copper speciation in highway stormwater runoff; 3) compare analytically determined free ionic copper (Cu2+free) concentrations in highway stormwater runoff with modeled concentrations; and 4) develop a qualitative understanding of where and when copper toxicity has the most potential to be problematic for receiving waters.
In this study, stormwater runoff from an urban high annual average daily traffic(AADT) site had consistently higher event mean concentrations of measured Cu2+diss and Cu2+free than the non-urban sites with lower AADT. First flush samples displayed consistently higher concentrations of both Cu2+diss and Cu2+free. A modified Competitive Ligand Exchange-Cathodic Stripping Voltammetry (CLE-ACSV) technique utilizing salicylaldoxime as an added ligand can be used to determine the speciation of copper in highway stormwater runoff. Analytical results from composite stormwater samples suggest that dissolved copper in highway stormwater runoff is largely complexed by organic matter (typically > 99.9%), and that very little of the copper in stormwater is bioavailable; the concentrations of Cu2+free were generally several orders of magnitudes below levels found to inhibit olfaction in Endangered Species Act listed fish species. Elevated Cu2+diss levels proved to be the greatest indicator of high Cu2+free concentrations.
Urban sites with AADT and first flush samples characterized by elevated concentrations of Cu2+diss are of the greatest concern with respect to elevated free ionic copper concentrations. Available dissolved organic matter models in Visual MINTEQ overestimate Cu2+free concentrations when compared to analytically determined Cu2+free concentrations. This imparts a conservatism that makes these models potentially useful for regulatory purposes.
Wireless Data Collection System for Real-Time Arterial Travel Time Estimates
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This project pursued several objectives conducive to the implementation and testing of a Bluetooth (BT) based system to collect travel time data, including the deployment of a BT-based travel time data collection system to perform comprehensive testing on all the components. Two different BT-based travel time data collection systems were installed. The first system, composed of two DCUs, was installed on a corridor located in Salem, OR. Extensive testing was done on this system, including the collection of travel time samples. A second system composed of five DCUs was installed along 99W in the city of Tigard, OR. Very limited data collection was done on 99W due to the lack of network connectivity.
Six different antenna types were characterized using the two DCU BT-based travel time data collection system. The result of the antenna characterization tests showed that vertically polarized antennas with gains between 9 and 12 dBi are good candidates to support a BT-based travel time data collection system. Antennas with circular polarization do not seem to improve the performance, despite the lack of control regarding the orientation of BT-enabled devices in most applications. Travel time samples were also collected with this system. The results indicate that a trade-off exist between the number of samples obtained and the accuracy of these travel time samples. This trade-off is most likely the result of differences in road coverage areas provided by the different antenna types.
Red Light Running Camera Assessment
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In the 2004-2007 period, the Mission Street SE and 25th Street SE intersection in Salem, Oregon showed relatively few crashes attributable to red light running (RLR) but, since a high number of RLR violations were observed, the intersection was identified as having a high crash potential. ODOT approved the installation of RLR cameras for a trial period to study the results of RLR cameras. Cameras were installed in February 2008 in the westbound and northbound directions.
A before and after study of the crashes involving westbound and northbound drivers at the Mission and 25th intersection was completed. In the 50 months prior to the camera installation crashes averaged 0.62 per month. In the 21 months after installation, the average increased by 77.4% to 1.10 per month.
Crash cost estimates for different types of crashes make it possible to account for the expectation that RLR cameras are likely to result in fewer angle crashes, which are often severe, and more rear end crashes, for which injuries tend to be less severe. The estimated average monthly crash costs increased from $16,296 before the cameras were installed to $27,738 after the cameras were installed.
Crashes increased only slightly or not at all at two comparison intersections, whereas the crashes increased substantially at the Mission at 25th intersection. Since traffic volumes declined slightly from the pre- to post-installation periods, the crash data were not normalized.
After camera installation, violations decreased by 43 percent in the westbound direction and 23 percent in the northbound direction. At both the westbound and northbound approaches, left turning vehicles accounted for the overwhelming majority of the violations.
Recalibration of the GRLWEAP LRFD Resistance Factor for Oregon DOT
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The Bridge Section of the Oregon Department of Transportation (ODOT) is responsible for the design of all bridge structures and routinely uses GRLWEAP for controlling pile driving stresses and establishing capacity from the bearing graph. The LRFD resistance factor, φ, for GRLWEAP sets the factored amount of nominal capacity in the LRFD inequality. Foundation conditions throughout Oregon’s Willamette Valley and the Portland metropolitan area are predominantly sand, silt, and clay. Steel pipe and H section foundation piles typically are of sufficient length to be friction piles and exhibit set-up after the end of initial driving (EOID). The two objectives of this study were to build an extensive database of driven pile case histories to include restrike conditions from the present available sources that reflect ODOT’s diverse soils and piles, and to establish φ factors for EOID and beginning of restrike (BOR) conditions using GRLWEAP to match ODOT practice.
A diverse group of existing databases, including the FHWA-built DFLTD and NCHRP 507 PDLT2000, were accessed and merged with new cases from the literature to build a comprehensive database, called the Full PSU Master. Neither of these two national databases proved always correct for the large amount of source input required, with the largest source of anomalies and missing data being the blow count, especially at the BOR condition. Over 150 new cases were added to establish the Full PSU Master database containing 322 piles, with each case placed into one of three input tiers for statistical profiling to assist in preserving quality for the φ calibration. The Full PSU Master database then supplied 179 cases analyzed by FHWA static capacity software DRIVEN and by GRLWEAP for capacity prediction by the bearing graph. These predictions generated bias mean λ and COV statistics for a range of ODOT selected scenarios. The 322 piles ranged up to 40 inches in diameter, and up to 197 ft. in embedment length. The 179 analyzed piles ranged up to 36 inches in diameter and 167 ft. in embedment length and had driving blow counts up to 100 BPI. This research showed similar trends for GRLWEAP capacity as that reported in NCHRP 507 for CAPWAP capacity on the statistical effects from variables such as blow count ranges. Sub-grouping λ by blow count revealed a clear decay in easy driving mean λ and COV parameters when blow counts were ≤ 2 BPI. Above 2 BPI, little difference was found in these parameters, and no upper limit of statistical accuracy was identified. A clear difference in statistical sample characteristics existed between piles supported in predominately cohesive soils to those in cohesionless soils, and also between pile types.
For the ODOT case of redundant piles in groups, a reliability index β at 2.33 was used to establish φ resistance factors and φ/λ efficiency measures. Statistics for an initial ten scenarios were generated, and the First Order Second Moment (FOSM) resistance factor at EOID and BOR was reported, based on lognormal fits to the λ distribution. The final five ODOT selected scenarios to permit comparison to NCHRP 507 and to form a basis to design implementation measures underwent advanced Monte Carlo based probabilistic procedures using random number generation and the λ lognormal tail fits to provide EOID and BOR φ factors. Recommended resistance factors from the visual tail fit procedure on the likely best fit to ODOT practice scenario containing all soil and pile types were 0.55 and 0.4 for EOID and BOR respectively. Recommendations were made for a separate implementation activity, including additional φ calibration work based on the Full PSU Master including use of field measured hammer performance, CAPWAP based soil input parameters, and pile type.
Needs and Issues Survey
FY 2011 Oregon Transportation Needs and Issues Survey
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The Oregon Transportation Needs and Issues Survey was first conducted in 1993 and has been done roughly every two years. The latest survey was completed in the summer of 2010 (State fiscal year (FY) 2011). This report summarizes the results of the FY 2011 survey. For some reoccurring questions, results are also compared to past surveys.
Flexural Anchorage Performance at Diagonal Crack Locations
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Large numbers of reinforced concrete deck girder bridges that were constructed during the interstate system expansion of the 1950s have developed diagonal cracking in the stems. Though compliant with design codes when constructed, many of these bridges have flexural steel bars that were cut off short of the full length of the girders. When load-rating these structures, the current design specification check of tension reinforcement anchorage often controls the capacity of these bridges. The tensile force demand is controlled by the load-induced moment and shear, the number of stirrups, and the diagonal crack angle; however, little information is available regarding bond stresses developed with larger-diameter bars for full-size specimens in the presence of diagonal cracks.
This research used large-size specimens to investigate the influence of diagonal cracks near flexural cutoff locations on the behavior and strength of vintage reinforced concrete girders. Testing indicated that a diagonal crack crossing the development length of cutoff longitudinal bars may not necessarily control specimen failure. Analysis showed that the required tensile demand at a diagonal crack location as predicted by AASHTO LRFD was reasonable. Two analytical methods and a non-linear finite element method were investigated for predicting the failure mode and capacity of the laboratory beams.
A procedure was developed to rate existing bridges for flexural anchorage requirements around cutoff locations. Cracking characteristics indicative of flexural reinforcement slippage were defined for bridge inspection.
Evaluation of Thin Overlays for Bridge Decks
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Eight thin polymer overlay systems were evaluated in the laboratory and on two bridge decks exposed to trucks and passenger vehicles including those with studded tires. The products were Mark 154, Flex-O-Lith, Safetrack HW, Kwik Bond PPC MLS, Tyregrip, SafeLane HDX, Urefast PF60, and Unitex ProPoxyType III DOT. None of the overlay systems showed superior performance under moderate average daily traffic from the standpoint of maintaining good skid resistance and resisting wear through. Tyregrip and Safetrack HW started to wear through to the concrete after exposure of approximately 1.3 million vehicles, and Urefast PF60 wore through much sooner. For the five products that did not wear through, empirical equations predicted the friction number of the best of these five products would decrease to 40 (equivalent to the friction number of the concrete) within five months at a traffic level of 10,000 vehicles per lane per day. Delamination from the concrete was not a major problem with the products. Laboratory tests were not able to predict performance.
Abrasion-Resistant Concrete Mix Designs for Precast Bridge Deck Panels
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The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) resistance and the durability of bridge decks. Phase I of the project involved an initial investigation of candidate mixtures incorporating type I portland cement, supplementary cementitious materials (silica fume, slag, and fly ash), natural aggregate (river gravel), and crushed rock. Three laboratory-curing methods were utilized in this effort including ordinary water curing and two accelerated steam-curing methods. A Pilot Study was undertaken to refine the laboratory steam curing methods as well as to determine if the duration of Oregon Department of Transportation’s (ODOT’s) field curing requirement for cast-in-place (CIP) bridge decks could be shortened. Phase II of the project utilized the findings from Phase I and the Pilot Study to develop HPC mixtures that had improved abrasion resistance and durability characteristics relative to a newly-specified ODOT bridge deck mixture. The mixtures investigated in Phase II incorporated type III portland cement and the same supplementary cementitious materials and natural aggregate that were used in Phase I. The silica fume content was varied in Phase II (i.e., 4%, 7%, and 10%), but held constant at 4% in Phase I.
Findings from Phase I indicated that mixtures containing a combination of silica fume and slag clearly had superior abrasion resistance, durability characteristics, and compressive strength relative to the mixtures containing a combination of silica fume and fly ash, and that the mixtures with crushed rock clearly outperformed those with river gravel in terms of abrasion resistance and strength characteristics (durability characteristics were essentially unaffected by aggregate type). Findings from the Pilot Study indicated that steam curing followed by application of a curing compound prior to ambient curing provided strength characteristics similar to that of concrete cured continuously in water, and that the 14-day field curing requirement for CIP bridge decks could be shortened to as few as 3 days without sacrificing 28-day strength provided that adequate measures are taken to ensure that the HPC is kept in saturated conditions.
Three HPC mixtures were developed under Phase II of the study that provided better wear resistance, durability characteristics, and strength properties than ODOT’s newly specified HPC for bridge decks (fabricated with fly ash at a w/b ratio of 0.30). All contained silica fume and slag and had w/b ratios of 0.30 or less. One did not contain entrained air. Overall, the mixture with the same mix design as ODOT’s newly specified HPC, except with slag in lieu of fly ash, provided the best balance between initial costs and enhanced performance.
Improving Commercial Motor Vehicle Safety in Oregon
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This study addressed the primary functions of the Oregon Department of Transportation’s (ODOT’s) Motor Carrier Safety Assistance Program (MCSAP), which is administered by the Motor Carrier Transportation Division (MCTD). The study first documented Oregon’s MCSAP enforcement performance in relation to its counterparts in other states. Cluster analysis was then employed to identify Oregon’s peer states with respect to MCSAP enforcement performance and a variety of other factors related to the motor carrier travel and safety environments. Structured interviews of peer state MCSAP personnel were then conducted to identify performance-improving strategies and practices that could potentially be implemented in Oregon. The feasibility of implementing these strategies and practices was then assessed against selected criteria.
Enhancements to Pavement Marking Testing Procedures
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The Oregon Department of Transportation (ODOT) requires performance and durability testing of all pavement marking materials before they can be applied on construction projects on state highways. Manufacturers apply materials on a two-year test deck where the product is evaluated regularly until a determination can be made regarding the suitability of the marking material. If it is determined that the material is suitable, it is included on the Qualified Products List (QPL). The testing and evaluation on ODOT test decks are limited to measuring the thickness of the marking material; assessing dry weather retroreflectivity; and subjective evaluations of appearance and durability. It was determined that a review of pavement marking testing procedures especially those followed in states with climatic conditions similar to Oregon could be useful. The research project includes recommendations to enhance the pavement marking testing and selection process. The recommendations relate to application procedures, monitoring and evaluation, and final selection of products. Proposed minimum retroreflectivity requirements are discussed.
Multimodal Freight Investment Criteria
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Literature was reviewed on multi-modal investment criteria for freight projects, examining measures and techniques for quantifying project benefits and costs, as well as ways to describe the economic importance of freight transportation.
A limited assessment of how investment decisions are made in Oregon was conducted by examining projects selected for the Connect Oregon II program (other funding programs exist, which use different approaches in selecting projects – Connect Oregon was selected because it is a multimodal program). To compliment the investigation of investment decisions, stakeholder opinions on multimodal freight needs and issues were also solicited.
From the literature review and survey of stakeholders, new and supplemental multimodal freight investment criteria were highlighted.
Density Measurement Verification for Hot Mixed Asphalt Concrete Pavement Construction
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Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected service life of the pavement. Currently, the ODOT Standard Specifications call for density measurements for both quality control and quality assurance testing to be made using nuclear density gauges that are calibrated using reference blocks. Hence, acceptance (i.e., purchase) of the HMAC pavement (or portions thereof) relies on the accuracy of the measurements. However, it has been observed that density measurement results using nuclear gauges have been questionable on a number of projects and that repeatability and reproducibility with the same gauge and between gauges have also been unattainable. Further, these observations have called into question the confidence placed in the use of nuclear gauges for determining HMAC pavement density.
The overall objective of the project was to recommend a system that accurately quantifies density of dense-graded HMAC pavements. This involved critically evaluating how ODOT currently measures HMAC density, investigating and evaluating what other agencies do to measure HMAC density, and conducting testing and analysis of alternate ways of measuring HMAC density (e.g., by measuring the density of cores).
Crack Sealer Fill Characteristics
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Laboratory testing was conducted to determine the extent of crack fill for crack sealers composed of methyl methacrylate, epoxy, urethane, and high molecular weight methacrylate. The test specimens consisted of eight-inch long concrete cylinders with a nominal 0.010 in. crack running the length of the cylinders and unsealed at the bottom. The following observations were made: all the sealers leaked to some degree from the bottom of the crack; thinner crack widths were more likely to be filled than wider crack widths; the fraction of the crack length filled in a cross-section through a cylinder was independent of the distance below the resin reservoir situated at the top of the crack; and a minimum of 70% crack fill was needed to prevent water leakage.
Licenses and ID to Prisoners
Issuance of Driver Licenses and Identification Cards to Prisoners
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In 2009, the Oregon Legislature passed House Bill 2489, requiring the Oregon Driver and Motor Vehicle (DMV) Services Division and the Department of Corrections (DOC) to enter into agreements and adopt rules to assist offenders in obtaining a driver license or identification (ID) card prior to release from prison. To assist in this effort, a research project was initiated to investigate issuance alternatives and study program feasibility.
As part of the research, various issuance agencies in other states were contacted to determine if they had or have a program for helping inmates obtain a license or ID card. Additional information was gathered from agencies with programs and a list of issuance alternatives was developed. The alternatives selected for a more detailed assessment included: mobile units, operation of a DMV field office within a DOC facility, using DOC personnel to process applications, and transporting inmates to DMV field offices. Each of these alternatives was assessed based on information obtained from other state agencies utilizing similar structures, data from the Oregon DMV and DOC, and data generated from a pilot test of inmate transportation conducted in Oregon. Each alternative was assessed using multiple criteria, including security, costs, personnel requirements, and system capacity, which are summarized in this report.
Analysis of QA Procedures at the Oregon Department of Transportation
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This research explored the Oregon Department of Transportation (ODOT) practice of Independent Assurance (IA), for validation of the contractor’s test methods, and Verification, for validation of the contractor’s Quality Control (QC) data. The intent of the project was to discover whether adjusted or additional processes for comparison between ODOT’s test results and the contractor’s test results may be available to improve confidence regarding whether the contractor’s test results are reliable. It was found that ODOT utilizes a combination IA/Verification process that uses the comparison of single results for its IA and Verification decisions. Based on statistical principles, published literature, FHWA guidance, and a small case study, recommendations were made that ODOT establish the breadth of systematic testing bias and that the IA and Verification processes be enhanced to include statistically-based comparison tests, including the often-used t-test and F-test.
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This report examines the use of lane-sharing (also sometimes referred to as lane-splitting and filtering) nationally and internationally and includes discussions on motorcycle and driver (auto) safety, and the potential benefits of lane-sharing.
A Study of the Wearing Caused by Studded Tires on Oregon Highways
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Oregon highways are experiencing significant wear damage in the wheel paths on both bituminous and concrete pavements. The main cause of this damage is from studded tires which create the problem of wear rutting on road surfacing in the wheel path areas. In a field study on Oregon roads, sites which had a potential for damage by studded tires were selected and rut measurements were taken. This, together with traffic volume data, showed the extent of the damage in different parts of the state. The field study found that the wear rate (i.e. wear/year) is greater in high traffic volume roads. Furthermore, on multi-lane highways, the rut depth is normally greater in the fast traffic lanes rather than the slow lanes.
Aggregate types and quality is probably the most important parameter that can contribute to a mix in resisting wear. A good aggregate would have the following primary properties in AC and PCC pavements: high resistance to wear; good bond with the binder and AC mixes; and no adverse reactions in concrete.
In the above mentioned field survey of Oregon highways, rut depth measurements from the selected sites, located in various regions in Oregon, were performed using a straight edge. By comparing sites with similar pavement condition (i.e. equal age, traffic, climate and mix type), it was concluded that the aggregate type and quality are the most important parameters that influence the pavement resistance to wear.
The aggregate sources in each site were identified from construction records. Routine ODOT Specification testing and Nordic abrasion resistance testing (i.e. Ball Mill) were carried out to evaluate the properties of the aggregates. It was found that some of these tests (e.g. Los Angeles abrasion) do not correlate with the actual field wearing and the correlation of others (e.g. Ball Mill abrasion) were rather poor. In addition, a detailed petrographical examination was performed on the selected aggregates. Based on this latter and other laboratory test results, the selected aggregates were classified in different categories according to their qualities. Finally, the aggregate properties which resisted studded tire wear were determined and specific recommendations for aggregate type selection and wear testing were proposed.