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Active Projects II

SPR 769

Safe and Effective Speed Reductions for Freeway Work Zones Phase 2 

 
Project Coordinator:
Jon Lazarus
Research Agency:
Oregon State University
Principal Investigator:
John Gambatese
Start Date for ODOT:
June 1, 2013
Completion Date for ODOT:
February 28, 2015
 
OVERVIEW:
In response to requests from the Associated General Contractors (AGC) Oregon-Columbia
Chapter, ODOT began a research study in FY2013 (SPR-751) to look for ways to safely reduce
speeds through work zones on preservation projects taking place on high-speed freeways.
Freeway preservation projects typically require traffic lane reductions to allow workers to
rehabilitate worn pavements. During lane closures, work activities take place immediately
adjacent to live traffic – traffic that is often travelling at high speeds. ODOT is interested in
strategies to safely reduce these speeds and subsequently improve the overall safety of the work
zone for drivers and for workers.
Phase 1 of this study (SPR 751) included two paving projects, one on I-84 near The Dalles and
one on I-5 just north of the McKenzie River Bridge. On each project, different traffic control
measures (TCMs) were implemented and speed data was collected both prior to and within the
work zone.
 
OBJECTIVE:
The proposed research comprises augmenting the SPR-751 study to address the issues and needs
identified by the TAC. This proposal includes conducting two additional case study projects at a
reduced cost. The additional case studies will be on paving projects similar to SPR-751, and
include a reduced total number of treatments focused on the following specific traffic control
measures: “SPEED 50” signs, PCMS signs on a roller(s) or a stationary trailer(s), and radar
speed reader trailers. As with SPR-751, the overall goal of the proposed research is to assist
ODOT with enhancing the safety of work zones on high-speed roadways.
 
Safe and Effective Speed Reductions for Freeway Work Zones Phase 2 Work Plan

QUARTERLY REPORTS
FY 14
FY 15
 
 
 
 qtr. 3
 
 
 
 
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SPR 770

Impact of Cascadia Earthquake on Seismic Evaluation

 

Project Coordinator:
Steve Soltesz
Research Agency:
Portland State University
Principal Investigator:
Peter Dusicka
Start Date for ODOT:
December 16, 2013
Completion Date for ODOT:
March 31, 2016
 
OVERVIEW:
The seismic risk used for bridge design and retrofit is defined by hazard maps of ground
acceleration values. To generate the maps, an algorithm called a Probabilistic Seismic Hazard
Analysis (PSHA) is used to combine multiple regional sources of ground shaking. Each source
has a different intensity, probability of occurrence, and distance to a specific location. For
Oregon, one key source of ground shaking in the PSHA is from the Cascadia Subduction Zone
(CSZ); however, a CSZ earthquake can have significantly different ground motion as a
standalone event than what is captured in the values derived from the PSHA.
 
OBJECTIVE:
The objective of this project is to provide ODOT with the best rational estimate of ground
acceleration values for designing and retrofitting bridges.
 
Impact of Cascadia Earthquake on Seismic Evaluation Criteria of Bridges Work Plan
 

QUARTERLY REPORTS
 
FY 14
FY 15
 
 
 
 
 ​qtr. 3
 
 ​qtr. 4
 
 
 
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SPR 771

Risk Factors Associated with High Potential for Serious Crashes

 

Project Coordinator:
Mark Joerger
Research Agency:
Montana State University
Principal Investigator:
Ahmed Al-Kaisy/David Veneziano
Start Date for ODOT:
November 21, 2013
Completion Date for ODOT:
May 26, 2015
 
OVERVIEW:
Crashes are random events and consequently, can occur at any location along the roadway. On
roadways with higher traffic volumes, the more frequent occurrence of crashes allows for the
direct identification of high crash locations using historical data. However, on local roads, crash
occurrence, particularly fatal and serious injury crashes, is less frequent. This makes it difficult
to identify trends and treat hazardous sites based on historical data. Geometric, traffic and other
features may lend themselves toward crashes potentially happening in spot locations. Therefore,
an approach to identifying these types of risk factors on low volume roads is necessary.
 
OBJECTIVE:
The proposed research will identify risk factors and features that contribute to crashes along low
volume roads and the cost effectiveness of countermeasures to address them. Research objectives
include:
Identify risk factors and features that contribute to crash occurrence and which can be corrected
by selected low cost countermeasures, with a specific focus on low and moderate volume roads
with sporadic crash occurrence.
Develop a risk index of different factors and features that practitioners should look for and that
can be addressed using selected low cost countermeasures along low and moderate volume
roads.
Establish the cost effectiveness/thresholds for the low cost countermeasures that are selected for
use in addressing risk factors on low to moderate volume roads.
Conduct limited case studies to demonstrate the use of the identified risk factors and application
of the cost effectiveness thresholds that are developed.
 
Risk Factors Associated with High Potential for Serious Crashes Work Plan

QUARTERLY REPORTS
 
 
 
FY 14
FY 15
 
 
 
 
 qtr. 3
 
 
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SPR 772

Investigation of Bicycle and Pedestrian Count Technologies

 

Project Coordinator:
Lyn Cornell
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 
 

OVERVIEW:

The Oregon Department of Transportation (ODOT) maintains a statewide license to traffic signal controller software (Northwest Signal Voyage) which has a red clearance (all-red) extension feature to dynamically extend the red clearance if a vehicle is detected that has or will likely run the red signal indication. This smart, adaptive red clearance treatment provides additional safety protection when risks of a RLR event is high, but is passive in other cases, thus having almost no impact on intersection capacity & delay. The cost is very low to implement this smart intelligent transportation system (ITS) treatment and over 500 intersections currently have controllers with this software feature available to them (and that number is growing). While widely available in Oregon, little is known about the impacts of this feature on intersection safety or best practice for detector placement and settings to maximize the safety/crash reduction benefits of the red clearance extension feature. Preliminary research suggests that detector placement is critical to achieving optimal benefits. This research would develop quantitative information about the safety effects of red clearance extensions from simulated data and available empirical data. The there is a clear opportunity to leverage the controller and software investments to larger safety gains and provide ODOT the opportunity to provide leadership on an issue of national importance. The value of this research is potentially high. 

OBJECTIVE:

 The overall goal of the proposed research is to quantify the safety performance of alternative red clearance extension detection and controller settings to mitigate RLR crashes at intersections in Oregon. More specifically, the objective is to determine where detection zones should be placed so as to maximize RLR crash avoidance potential (detection further away from the stop bar), while minimizing the likelihood of false red light extensions (extension is triggered for a stopping vehicle), and to establish optimal timing parameters for various objectives. 

Investigation of Bicycle and Pedestrian Count Technologies Work Plan

 

QUARTERLY REPORT

 

FY 15
FY 16
 
 
 
 
 
 
 
 
 

 

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SPR 773

Optimal Timing and Detection Practices for Red Clearance Extensions
 
Project Coordinator:
Mark Joerger
Research Agency:
Oregon State University
Principal Investigator:
David Hurwitz
Start Date for ODOT:
July 1, 2014
Completion Date for ODOT:
March 1, 2016
 
OVERVIEW:
The Oregon Department of Transportation (ODOT) maintains a statewide license to traffic signal controller software (Northwest Signal Voyage) which has a red clearance (all-red) extension feature to dynamically extend the red clearance if a vehicle is detected that has or will likely run the red signal indication. This smart, adaptive red clearance treatment provides additional safety protection when risks of a RLR event is high, but is passive in other cases, thus having almost no impact on intersection capacity & delay. The cost is very low to implement this smart intelligent transportation system (ITS) treatment and over 500 intersections currently have controllers with this software feature available to them (and that number is growing). While widely available in Oregon, little is known about the impacts of this feature on intersection safety or best practice for detector placement and settings to maximize the safety/crash reduction benefits of the red clearance extension feature. Preliminary research suggests that detector placement is critical to achieving optimal benefits. This research would develop quantitative information about the safety effects of red clearance extensions from simulated data and available empirical data. The there is a clear opportunity to leverage the controller and software investments to larger safety gains and provide ODOT the opportunity to provide leadership on an issue of national importance. The value of this research is potentially high.
 
OBJECTIVE:
The overall goal of the proposed research is to quantify the safety performance of alternative red clearance extension detection and controller settings to mitigate RLR crashes at intersections in Oregon. More specifically, the objective is to determine where detection zones should be placed so as to maximize RLR crash avoidance potential (detection further away from the stop bar), while minimizing the likelihood of false red light extensions (extension is triggered for a stopping vehicle), and to establish optimal timing parameters for various objectives.  
 
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 774

Road User Charge Economic Analysis
 
Project Coordinator:
Brooke Jordan
Research Agency:
Oregon State University
Principal Investigator:
B. Starr McMullen/Haizhong Wang
Start Date for ODOT:
 
Completion Date for ODOT:
 

 

OVERVIEW:
The Oregon Department of Transportation (ODOT) relies on the fuels tax to fund road infrastructure maintenance, operations, and improvements. The fuels tax has been a reliable source of transportation revenue for decades, but increasing vehicle fuel efficiency and other factors are expected to result in permanent funding shortfalls, however, fuel tax revenues are a significant share of state highway fund revenues.  Therefore, Oregon’s highway system would be in jeopardy as the gasoline tax revenues necessary to maintain, preserve and modernize the system slowly but steadily drained away. In 2007, ODOT completed its first pilot project, which resulted in valuable lessons that were applied to the second pilot project, completed in early 2013. The purpose of this study is to assess the economic impacts of various alternative road user charge structures and implementation proposals on stakeholders in the state of Oregon. 
 
OBJECTIVE:
The objective of this research is to provide ODOT with up to date information on the economic impact of various RUC alternatives on the stakeholders in the state of Oregon.  This information can then be used to make informed decisions on which VMT fee structure to adopt in the transition between the current finance structure and a sustainable finance structure for the future.  Previous work in the area was limited by the small Oregon sample of households included in the NHTS data set.  The newly available OHAS opens the opportunity to explore the impacts on Oregon households and geographic regions with much greater precision.  Further, the OHAS data set provides a much larger sample of alternative fuel, hybrid, and fuel-efficient vehicles than included in past data sets. 
This proposed research project will analyze the economic impact of various road user charge rate structures and implementation strategies. Possibilities that could be explored include: (1) A simple flat rate structure that applies to all vehicles. (2) A transition VMT fee structure that could, at first, retain the gasoline tax for existing vehicles but impose a VMT fee structure on new vehicles starting in a specified year (the VMT fee could be either a flat fee or a vehicle efficiency based fee) 3) An alternative transition VMT fee imposed only on existing fleet vehicles with mpg>50, or >40 or >30.  These fees structures could be supplemented at the state or local level with vehicle or facility specific rates.  Hybrid or transition systems such as 2) or 3) would probably involve higher calculation, storage, and other associated implementation costs.
In all cases the impact on identified socio-economic groups and regions will be assessed as well as the impact on financial stability of the system.
 
Road User Charge Economic Analysis Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 775

Titanium for Strengthening Existing Reinforced Concrete Bridges
 
Project Coordinator:
Steve Soltesz
Research Agency:
Oregon State University
Principal Investigator:
Chris Higgins
Start Date for ODOT:
 
Completion Date for ODOT:
 

  

OVERVIEW:
Oregon has many reinforced concrete bridges that were built in the 1950’s. The bridges from this era commonly have poor reinforcing details such as longitudinal reinforcing bars terminating in areas under stress, inadequate bar splices, and insufficient vertical reinforcement. Consequently, these older ODOT bridges often are evaluated as deficient and require remediation. It is anticipated that on-going load rating and evolving loading requirements will uncover many deficient bridges for years to come.
Current practice and previous ODOT research provide design options for strengthening. A common option is to bond carbon fiber reinforced polymer (CFRP) strips either on the surface or just below the surface. The method relies solely on the adhesive bond to transfer stresses to the CFRP; consequently, the full strength of the CFRP is never utilized because the concrete near the bond fails first. To compensate for the relatively weak bond, more strips are installed to distribute stresses across more bond surfaces. If space is not available for more strips, a more elaborate strengthening scheme may be deployed.

In a current ODOT-funded research project, a titanium alloy bar has been developed that has high-strength and high ductility and is impervious to environmental degradation. The bar can be produced over a wide range of sizes. Unlike CFRP, a key feature of this material is that it can be bent. Consequently, the ends of the titanium bar can be bent to ninety degrees and embedded deep into a beam that needs strengthening. This mechanical anchorage overcomes the problem of the weak bond and allows the titanium reinforcing material to utilize its high strength. These characteristics make it both a structurally and economically effective choice over CFRP and other alternatives.

Based on the current research, a titanium retrofit will be deployed on a bridge over I-84. In the strengthening design, the number of supplemental reinforcement elements per girder line was reduced from twelve for CFRP to four for titanium. The retrofit is expected to be less costly and have better structural performance than CFRP.

The characteristics of titanium reinforcement, particularly its ability to be bent, open up possible cost savings for a wide range of strengthening situations. Three areas listed in the Research Objectives have been identified for further research to exploit the advantages of titanium reinforcement for strengthening.
OBJECTIVE:
The research has three objectives to expand the use of titanium reinforcement: (1)Develop a splicing method that allows supplemental reinforcing bars to be deployed along the full length of girders including through the intermediate diaphragms that protrude from most beams. (2) Develop an unbonded strengthening detail that eliminates the need to cut grooves into the concrete surface, thereby reducing labor costs, epoxy material costs, and construction time. (3) Develop methods to apply exterior titanium bars to strengthen girders with inadequate transverse reinforcement.
 
Titanium for Strengthening Existing Reinforced Concrete Bridges Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 776

Quantifying Noise Impacts from ODOT Aggregate Source Operations
 
Project Coordinator:
Matthew Mabey
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 

  

OVERVIEW:
The potential listing of the sage grouse as “endangered” by US Fish and Wildlife (expected in 2015) has the potential for significant impact to ODOT aggregate source operations. Oregon Department of Fish and Wildlife (ODF&W) has issued a whitepaper in 2012 that provides interim guidance for mitigation for sage grouse habitat from activities associated with industrial-commercial developments. Such developments include rock quarries. The interim guidance provides requirements for decibel thresholds, use of propagation models with output binned in 5-decibel contours, and recommended mitigation. It is unknown if activities from ODOT aggregate source sites comply with these very low noise thresholds. This uncertainty has potential impacts to development and delivery of projects in Regions 4 and 5 that depend heavily on material from ODOT quarries. Data are needed to determine compliance with the decibel thresholds and identify potential mitigation. There is also a great need to collect data for development of a methodology that can be applied throughout the state for determining noise impacts to sage grouse habitat and habitat for other noise sensitive species as well as other noise sensitive uses from rock quarries.
 
OBJECTIVE:
The key objective of this project is to establish how noise produced by ODOT aggregate source operations compares to standards being put forward to protect sage grouse populations. 
 
Quantifying Noise Impact from ODOT Aggregate Source Operations Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 777

Chip Seal Design and Specifications
Project Coordinator:
Jon Lazarus
Research Agency:
Iowa State University
Principal Investigator:
Douglas Gransberg/Chris Williams
Start Date for ODOT:
 
Completion Date for ODOT:
 

 

OVERVIEW:
Thin preservation treatments are becoming more important because of their success to extend pavement life and the high cost of total road rehabilitation. Hicks et al. (2000) reported that for every dollar spent on maintenance before the age of rapid deterioration saves $6 to $10 in future rehabilitation costs. Chip sealing is a common preventive maintenance tool that results in more economical pavements as a result of pavement life extension. Chip seals are the main tool that ODOT uses for preservation of low volume roads and use has expanded to all types of facilities, including the interstate. Our chip seal program comprises approximately $7 million per year. The budget allocated for chip seals is cost effective and covers an extensive amount of lane miles. In past years, chip seals were predominantly applied by Maintenance crews, however, now ODOT is outsourcing a portion of this work to contractors who need better guidance.
The technique used to apply chip seals is currently referred to as more of an ‘art’ than ‘science’. The method involves an experienced person conducting a visual inspection during the application and making adjustments in binder and/or aggregate (chip) rate. Many of the experienced individuals within ODOT are nearing the end of their careers or have already retired. Over the last two construction seasons, there have been multiple failures. One project had to be repaved the following season at a cost of $1.8 Million. Also, when proper chip embedment is not achieved, there is potential for windshield claims. In another case, the claims totaled more than the actual project cost. There are design tools available which use math and science to select appropriate shot rates for binder and chips which could improve success. NCHRP Synthesis 342 reported that more quantitative methods are becoming available and these methods can lead to improved performance. These quantitative tools are used by other agencies both in the USA and internationally. A commonly accepted methodology is the McLeod Method. New Zealand (NZ), United Kingdom (UK), South Africa (SA), and Australia (AU) all have quantitative design procedures for design and construction of chip seals. ODOT’s specifications need to be revisited to ensure the agency is: a)providing better guidance to Maintenance crews and contractors, b)conducting the appropriate tests and construction practices, and c)providing the best-quality product to reduce the risk of claims.
 
OBJECTIVE:
The objective of this research is to document methods and report the performance of chip seals designed using different methodologies. Once quantified, the research will identify best practices that can be implemented. 
 
Chip Seal Design and Specifications Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 778

Safety Effectiveness of Pedestrian Crossing Enhancements
 
Project Coordinator:
Lyn Cornell
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 

 

OVERVIEW:
Data-driven safety decision-making–including implementation of the Highway Safety Manual–requires the development of crash modification factor (CMFs) for various roadway improvements. Over the last decade, the Oregon DOT has systematically implemented many pedestrian crossing enhancements (PCEs) across the state. The most commonly deployed treatments include continental crosswalk markings, pedestrian median islands, curb bulb outs, pedestrian activated flashing beacons and advanced stop bars. The existing literature on driver yielding clearly indicates that medians are a significant pedestrian safety feature and pedestrian-hybrid beacons improve driver stopping compliance (both of these are included in the FHWA countermeasures clearinghouse). Rectangular Rapid Flash Beacons (RRFB) also improves yielding but the safety effects have not yet been quantified.
Still, many questions remain regarding the quantification of the positive impact of PCEs on overall crashes (i.e. medians may also reduce vehicle crashes) and the transferability of national results. As driver behavior and culture vary, estimates of safety effects are more accurate and relevant when developed from a robust, local data set. In Oregon, installations of crosswalks on state highways at mid-block or uncontrolled intersections require the approval of the State Traffic-Roadway Engineer (STRE). A careful integration of the well-documented installations of PCEs across the state with relevant traffic, roadway features, and land use data presents provide a unique opportunity to conduct robust research to estimate measures of PCEs safety effectiveness in the Oregon design contexts for improved data-driven decisions.
 
OBJECTIVE:
The objective of this research is to estimate, as robustly as possible, the effectiveness of PCEs on multimodal safety in Oregon design contexts (i.e. not only pedestrian crashes but also motorized vehicles and bicycle crashes in the vicinity). This research will carefully consider the type of enhancement, the geometry, the surrounding land uses, and pedestrian/vehicle exposures. The results of this research will provide high value to decision-makers and will guide future PCE deployments. The results of this research can also set the foundation for future cost/benefit analysis of PCEs.
 
Safety Effectiveness of Pedestrian Crossing Enhancements Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 779

Risk Factors for Pedestrian and Bicycle Crashes
 
Project Coordinator:
Mark Joerger
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 
 
OVERVIEW:
In Oregon, pedestrian and bicyclist fatalities comprise more than 15% of all traffic deaths and are of primary concern for many communities in Oregon (there were 56 bicycle and 247 pedestrian fatalities in the last five years). Oregon has identified pedestrian and bicycle crashes as a primary focus area for investing infrastructure funding and has marked approximately $4 million in the All Roads Safety Program to help address this key need. However, developing a plan for targeted investments is challenging because pedestrian and bicycle crashes are uncommon enough to make it difficult to predict where they will occur next. This random nature also makes it difficult to identify high crash locations and corridors. The identification of risk factors and the magnitude of their influence on the likelihood of future crashes were significantly constrained by limited roadway information used in the analysis such as bicyclist and pedestrian volumes, the presence of a crossing treatment, presence of a turn lane, driveway activity, and sight distances. To improve ODOT’s ability to target limited resources more certainty is needed about the most important risk factors.
 
OBJECTIVE:
The objective of this work is to develop a tool for ODOT to improve methods to identify and prioritize locations with increased risk, rather than a simple crash history, so they can be proactively treated. Using the consultant’s work as a starting point, this research would continue to investigate the factors related to the common causes of pedestrian and bicycle crashes. This research will seek to identify key risk factors that contribute to higher than average numbers of serious or fatal pedestrian and bicycle crashes to generate best practices in pedestrian and bicycle problem identification and prioritization, and identify data elements that support decision making and prioritization.
 
Risk Factors for Pedestrian and Bicycle Crashes Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 780

Strategies to Increase the Service Life of Bridge Decks
 
Project Coordinator:
Steve Soltesz
Research Agency:
Oregon State University
Principal Investigator:
Burkan Isgor/ Jason Ideker/ David Trejo
Start Date for ODOT:
 
Completion Date for ODOT:
 
 
OVERVIEW:
Corrosion of the steel in reinforced concrete bridge decks is an important issue for structures that are exposed to chloride-containing de-icing chemicals or marine salts. Once the amount of chloride at the steel reaches a critical level, corrosion is likely to initiate. ODOT has a large number of bridges that are vulnerable to this form of deterioration. The cost of repairing or replacing bridge decks after corrosion initiation and damage is considerably high. Pre-emptive actions that prevent corrosion initiation are more cost effective than repair or replacement of bridge decks that have already experienced corrosion. An obvious indicator of a corrosion problem is visible damage; unfortunately, if corrosion damage is visible, the window for preventive action is likely closed.
ODOT uses chloride depth profiling on occasion to provide quantitative insight into the corrosion risk of bridge elements, but the method is time consuming and relatively expensive and is not practical for routine monitoring of bridge decks with current ODOT resources. Other measurement technologies are at various stages of maturity and are likely to be useful either by themselves or when used in combination. Whatever measures are used, values need to be turned into predictions about time to corrosion damage and when to apply pre-emptive action. Much valuable research is already available on detection technologies and models to predict corrosion.
Every year, ODOT treats the riding surface of select bridge decks with sealers, coatings and thin overlays to protect the decks from deicing chemicals. Currently, the decks are selected based on the judgment of field personnel occasionally with additional data from chloride profiles. There is no routine methodology in place to select decks based on quantitative measurements coupled with time-to-damage predictions. Fortunately, ODOT can exploit the extensive existing research to develop a selection protocol based on Oregon service conditions. 
 
OBJECTIVE:
The objective of the research is to provide ODOT with a protocol to select bridges for its ongoing bridge deck treatment operations using quantitative tools that are practical and quick.
 
Strategies to Increase the Service Life of Bridge Decks Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 781

Improving Adaptive/Responsive Signal Control Performance
 
Project Coordinator:
Mark Joerger
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 

 

 
OVERVIEW:
ODOT is turning towards adaptive/responsive signal control strategies to improve the operational performance of coordinated corridors and networks. However, these newer control strategies require more information from the detection systems than more traditional control strategies. This requirement for higher resolution detection data could be addressed through the selection of in pavement detection; however, due to the capital costs associated with in-pavement detection systems ODOT is increasingly selecting non-invasive or passive detection systems such as video cameras, micro-wave, radar, or micro detection pucks, which are also easier to install and maintain.

These non-invasive systems are currently performing below those standards established by the use of in-pavement detection. As such, ODOT is currently operating adaptive and responsive signal control by applying legacy timing and installation practices, and in doing so is not maximizing the benefits of its investment in advanced control strategies. The use of passive detection can degrade optimal intersection performance up to 20%, resulting in longer delays to the public, inefficient use of cycle time, increased traffic queuing, increased fuel consumption, increases risk of traffic crashes due to congestion and results in sub-optimal signal operations.

Current ODOT standards of practice for purchase, installation, layout and timing of non-invasive systems requires updating. More realistic costs, installation practices, detection zone layouts and timing parameters are needed in order to capture the full measure of the more powerful data driven traffic signal controller systems currently being deployed throughout the State of Oregon.
 
OBJECTIVE:
This research will develop a realistic installation guideline that supports the requirements of advance traffic signal controller operations, hybrid detection installations, and non-invasive detection optimization. This guideline shall provide prototypical detection configurations and new timing standards that reducing or eliminating performance degradation. These guidelines will include a cost analysis that appropriately considers equipment and installation costs as well as the cost of increase delay to the motoring public due to the degradation of signal performance. The costs of this delay can be as much as ($18 per delay hour per/day per passenger vehicle) and as much as ($70 per delay hour per/day per interstate transit vehicle).
 
Improving Adaptive/Responsive Signal Control Performance Work Plan
 
QUARTERLY REPORT
FY 15
FY 16
 
 
 
 
 
 
 
 
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SPR 782

HMAC Layer Adhesion Through Tac Coat
 
 
Project Coordinator:
Norris Shippen
Research Agency:
 
Principal Investigator:
 
Start Date for ODOT:
 
Completion Date for ODOT:
 
 

 

OVERVIEW:
Pavement layer adhesion is a major factor in the structural integrity of a pavement system. The inability of layers to adhere can cause premature cracking and lead to early pavement failure. This factor is even more important on thin HMAC wearing courses (<2”) which are becoming more common among highway preservation treatments. The main approach to layer adhesion has been through the emulsified tack coat. Tracking of the tack coat by construction equipment has always been an issue. It is taught that tack coat application is critical to performance, yet by the time the paver lays HMAC, most of the tack in gone. There are new asphalt emulsions being formulated that help combat this issue but are not yet refined enough for regular use or are pricey and proprietary.
 
OBJECTIVE:
Recent research on tack has been able to identify harder base asphalt for emulsions and optimum application rates to provide a better bond. NCHRP Report 712 developed the Louisiana Tack Coat Quality Tester (LTCQT), to evaluate the quality of the bond strength of the tack coat in the field. The LTCQT may be developed as a tool for the paving inspector to ensure an adequate tack is being applied and if the tack is ready for construction traffic to reduce the tracking potential of the tack coat.
 
HMAC Layer Adhesion Through Tac Coat Work Plan
 
QUARTERLY REPORT
 
FY 15
FY 16
 
 
 
 
 
 
 
 
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