mississippi spr-1(103), p ii - mdot.ms.govmdot.ms.gov/documents/research/reports/progress reports/fy...

Quarterly Progress Report 3rd Quarter FY 2017 April/May/June 2017

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MISSISSIPPI SPR-1(103), PART II

QUARTERLY PROGRESS REPORT

PERIOD: APRIL/MAY/JUNE 2017

FEDERAL FY 2017 3RD QUARTER


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Contents

State Study No. 263— Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements ............................................................................................................................... 4

State Study No. 264— District Traffic Control Support to Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements ....................................................................... 5

State Study No. 265— Research Division Support to Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements ............................................................................. 6

State Study No. 266— Field Aging Effects on Asphalt Mixed at Different Temperatures and Hauled Different Distances .............................................................................................................. 7

State Study No. 269— Development of a Setup Prediction Method and Implementation into LRFD Driven Pile Design in Mississippi soils .................................. 8

State Study No. 270— Continuation of Field Aging Effects on Asphalt Mixed at Different Temperatures and Hauled Different Distances Phase III .................................. 9

State Study No. 271— Knowledge of Effects of Different Mississippi Soil Deposits on Pavement Performance ............................................................................................................ 10

State Study No. 273— Update and Documentation of MDOT Warranty Process and Distress Thresholds .................................................................................................................. 12

State Study No. 274— Improving Federal Transit Administration (FTA) Transit Vehicle Procurement Process in Mississippi ....................................................................... 14

State Study No. 275— Intermodal Project Selection Criteria ........................................... 15

State Study No. 276— Soil-Cement Manual of Practice: Interconnected Framework for Pavement Design, Laboratory Mixture Design, and Construction Quality Control/Assurance .................................................................................................................... 16

State Study No. 277— Best Practices for Lighting and Marking Maintenance/ Construction Equipment for Safety ........................................................................................ 17

State Study No. 278— Calibration Factors for Safety Performance Functions .............. 18

State Study No. 279— High Quality Simulation Training .................................................. 19

State Study No. 281— Permeability Reduction of Restrained Concrete in a Chloride-Rich Environment ...................................................................................................................... 20

State Study No. 282— Traffic Signal Vehicle Detection, One Size Does Not Fit All ....... 22


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State Study No. 283— Adaptive Signal Performance Measures ....................................... 24

State Study No. 285— CSM Conversion Factors and Regression Parameters to Back Cast CSM Strength and Modulus ............................................................................................. 25


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State Study No. 263— Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements

Principal Investigator: Allen Cooley MDOT Project Monitor: William Barstis

Funds Allocated: $643,774.00 Start Date: 5/23/2017 Expended to Date: $0 Completion Date: 6/30/2019 Research Agencies: Burns, Cooley, and Dennis Objective: The Mechanistic-Empirical Pavement Design Guide (MEPDG) method for designing pavement structures utilizes mechanistic materials properties combined with other inputs to predict pavement performance using user inputs. Pavement performance models are used for this prediction of pavement performance. The pavement performance models are based upon national predictive models that are likely not applicable to Mississippi. This research project is designed to provide the required information for the calibration of these performance models for Mississippi materials and conditions. A number of test pavement sections will be visited, evaluated, sampled, and tested. Following these activities site reports will be prepared for each individual site that provides the information required for this calibration of the pavement performance models to local conditions.

Progress: During this reporting period, the project was initiated. Also, three of the 65 field projects were tested. Plans for next quarter:

During the next quarter, it is anticipated that an additional 6 to 10 field projects will be tested. Also, laboratory testing will be initiated. Employment Data for Burns, Cooley, and Dennis Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

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State Study No. 264— District Traffic Control Support to Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements

Principal Investigator: Alex Collum Funds Allocated: $250,000.00 Start Date: 5/23/2017 Expended to Date: $0 Completion Date: 6/30/2019 Research Agencies: MDOT Objective: The District in-house support to State Study 263 will cover traffic control and other District personnel field work and charges in support of the main study.

Progress:

Work began. Provided traffic control for testing sites.

Plans for next quarter:

Continue providing traffic control for testing sites.


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State Study No. 265— Research Division Support to Collection and Evaluation of Core Data for the MEPDG for Overlayed and New Pavements

Principal Investigator: William Barstis Funds Allocated: $550,000.00 Start Date: 5/23/2017 Expended to Date: $ 133,345.66 Completion Date: 6/30/2017 Research Agencies: MDOT Objective: The Research Division in-house support to State Study (SS) 263 will provide falling weight deflectometer (FWD) field testing and FWD data analysis to characterize in-situ moduli of pavement layers at each project site used for local calibration of MEPDG performance models. Extensive coordination between principal investigator of SS No. 263 and MDOT District traffic control personnel will be performed via this support study as well as review of site reports generated as a deliverable of SS 263.

Progress:

Work began. Performed testing procedures at coring sites.

Plans for next quarter:

Continue performing testing at coring sites.

Employment Data for MDOT Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

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State Study No. 266— Field Aging Effects on Asphalt Mixed at Different Temperatures and Hauled Different Distances

Principal Investigator: Isaac L. Howard MDOT Project Monitor: Alex Middleton

Funds Allocated: $150,000.00 Start Date: March 1, 2014 Expended to Date: $144,274.70 Completion Date: December 31, 2017 Research Agencies: Mississippi State University Objective: With all the options available to produce and place asphalt pavement in present day, a study into the field aging of these materials needs to be performed. Field aging has always been one of the biggest uncertainties in asphalt pavement performance, and with the widespread use of warm mix technologies, there are more aging questions than ever. This study is very timely, and if performed now can be conducted for less cost by leveraging the investment of a previous study.

Progress:

The project is nearing completion.

Plans for Next Quarter:

Plans for the next quarter are to work on all remaining tasks, as appropriate.

EEO and Title VI Information:

Employment Data for Mississippi State University Research Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

10 9 1


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State Study No. 269— Development of a Setup Prediction Method and Implementation into LRFD Driven Pile Design in Mississippi soils

Principal Investigator: Eric J. Steward MDOT Project Monitor: Alex Middleton

Funds Allocated: $149,000.00 Start Date: 1/9/2017 Expended to Date: $0 Completion Date: 6/30/2017 Research Agencies: University of South Alabama Objective: Geotechnical engineering, and pile driving in particular, contains a significant amount of uncertainties in the design process. At this point in time, a pile foundations’ increase in strength or bearing capacity, over time cannot be quantified. Determination of this long-term bearing capacity can influence both the required pile size and embedment depth and, in turn, would lower project costs considerably. This study intends to develop a pile loading database for MDOT as well as calibrate regionally specific resistance factors required for LRFD (Load Resistance Factor Design) for MDOT projects.

Progress:

Tasks C1 and M1: The research team began communication with the MDOT collaborators and initiated a "Kick-off" meeting (May 24, 2017). Another meeting was completed to allow collaborative efforts between the Graduate Student (Chip) and the design engineers at MDOT to share data and software (June 1). Task 2 has begun as the data is being organized.


Task 1 will be completed and Task 2, organization of the data will be the focus of the next quarter. Task 3, visiting test sites, will begin as a scheduled site visit is set for July 20.


Employment Data for University of South Alabama Research Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm 2 2


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State Study No. 270— Continuation of Field Aging Effects on Asphalt Mixed at Different Temperatures and Hauled Different Distances Phase III

Principal Investigator: Isaac Howard MDOT Project Monitor: Alex Middleton

Funds Allocated: $115,000.00 Start Date: 4/18/2016 Expended to Date: $30,596.62 Completion Date: 12/31/2019 Research Agencies: Mississippi State University Objective: With all the options available to produce and place asphalt pavement in present day, a study into the field aging of these materials needs to be performed. Field aging has always been one of the biggest uncertainties in asphalt pavement performance, and with the widespread use of warm mix technologies, there are more aging questions than ever. This study is very timely, and if performed now can be conducted for less cost by leveraging the investment of a previous study.

Progress:

Progress was made on five tasks. Task 1 saw 25% progress from literature review, Task 2 saw 17.15602% progress due to laboratory conditioning and testing, Task 3 saw 25% difference due to field aging and assessment, Task 5 saw 25% progress due to progress reporting, and Task 6 saw 29.61415% progress due to final report preparation.


Plans for the next quarter are to work on all tasks as appropriate.



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State Study No. 271— Knowledge of Effects of Different Mississippi Soil Deposits on Pavement Performance

Principal Investigator: Richard Sheffield MDOT Project Monitor: William Barstis

Funds Allocated: $44,104.74 Start Date: 5/31/2016 Expended to Date: $7,947.95 Completion Date: 12/31/2017 Research Agencies: Thompson Engineering Objective: MDOT S.O.P. TMD-20-14-00-000, “Centerline Soil Profiles and Standard Design Procedures for Construction of Roadways Through High Volume Change Soils,” specifies use of the Mississippi Office of Geology’s Geologic Map of Mississippi to identify the boundaries/areal extent of geologic units of various soil types distributed across the state. This S.O.P. references eight geologic units that include active clays requiring either replacement or treatment with lime. The MDOT Assistant Chief Engineer – Operations advised that MDOT does not construct rigid pavements within the “Loess” geologic unit due to the erodibility of this type soil. These examples demonstrate that given soil deposits impact selection of pavement type or construction practice.

Mississippi DOT is in the process of implementing the Mechanistic-Empirical Pavement Design procedure for designing rigid and flexible pavements. This effort includes providing the agency with a manual, “Mississippi DOT Pavement ME Design User Input Guide.” The current draft manual needs to be enhanced with the addition of a chapter focused on the various soil deposits located throughout the state.

This chapter will capture available institutional knowledge on the general properties of each geological unit of soil deposit and their effects on the performance of pavements constructed thereon. Given geological units requiring special pavement design or pavement foundation considerations will be addressed. This chapter will also list the geologic units that preclude construction of rigid pavements. It is envisioned that the Mississippi Office of Geology’s Geologic Map of Mississippi will be used as the basis for this chapter with accompanying discussion of each geologic unit and corresponding impact on pavement performance.

Progress:

TASK 6 - Worked on drafting changes to SOPs


TASK 2 - Continue review of materials provided by MDOT. TASK 6 - Submit draft SOP changes. TASK 7 - Begin Drafting final report.



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State Study No. 273— Update and Documentation of MDOT Warranty Process and Distress Thresholds

Principal Investigator: Feng Wang MDOT Project Monitor: Alex Collum

Funds Allocated: $200,000.00 Start Date: 8/26/2016 Expended to Date: $4,600.00 Completion Date: 12/31/2018 Research Agencies: Jackson State University Objective: MDOT implemented warranty specifications in the late 1990s as an option on construction/overlay projects. The specification included distress thresholds which, if exceeded, result in the contractor having to take action, from repair to remove and replace. MDOT seeks to do the following: (1) Document the existing warranty process; (2) Revisit the warranty thresholds to see if they need adjustment; and (3) Quantify the distress thresholds in terms of distress quantities and severities rather than deduct points.

Progress:

In the last quarter, the research team continued to do literature reviews, data and equipment acquisition, and statistical model selection in Tasks 1, 2 and 3. Then, started developing warranty distress threshold in Task 4. In June, the research team had a short meeting with Ms. Marta to receive update warranty maintenance reports, non-warranty measurements in PMS database, traffic data of warranty projects, and warranty project inventory data. After receiving these data, we continued data processing and analyses for the project.

From the received warranty maintenance reports of 21 pavement warranty projects, the distress measurement data were retrieved from these reports. The provided warranty pavement data included important traffic data AADT and AADTT. In addition, the research team also received the non-warranty pavement dataset in which distress data of survey time from 1991 to 2016 are saved. The warranty and non-warranty pavement data analyses are already under way. With the help of Ms. Marta, we have created an external account from MDOT to login PathWeb, where we could see the saved highway pavement video image data. The research team continues to use Non-parametric Bootstrap model to analyze the new non-warranty pavement data for all relevant distress types. The research team also continues to use the Survival Analysis model to analyze the pavement distress data and to evaluate the performance of the warranty pavements against the non-warranty pavements with an emphasis on distress thresholds. To date, about70% of Task 1, 50% of Task 2, 80% of Task 3, and 15% of Task 4 were completed during the QPR Period.


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Use Bootstrap model to analyze the distributions, calculate the medians, means, variances (standard deviations) and other statistic characteristics, and develop the distress cumulative distribution functions (CDF) curves of the new warranty and non-warranty pavements.

Use the selected Survival Analysis model to analyze the update warranty and non-warranty pavement distress data, and evaluate the survival probabilities over the service time of the warranty and non-warranty pavements in Mississippi.

Start to set up distress thresholds of MDOT pavement warranty program through data analyses and other research results in DOTs.

Add the traffic data AADT and AADTT as one of the most important influence factors and select other important influence factors into the analysis model.

Purchase the designated image process equipment and software. Make use of the PathWeb to get the characteristic of the video images, and discuss with MDOT engineers to learn how to use the image processing equipment and software.


Employment Data for Jackson State University Research Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

5 1 1 1 2


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State Study No. 274— Improving Federal Transit Administration (FTA) Transit Vehicle Procurement Process in Mississippi

Principal Investigator: Randy Battey MDOT Project Monitor: Cindy Smith, P.E.

Funds Allocated: $74,754.22 Start Date: 9/20/2016 Expended to Date: $41,335.91 Completion Date: 12/31/2017 Research Agencies: Gresham, Smith, and Partners Objective: This study will examine FTA transit vehicle procurement compliance requirements and those of DFA to identify inconsistencies and bottlenecks, and to streamline the process. The principal investigator (PI) will research and clearly delineate all applicable federal and state level regulations and requirements and recommend ways that MDOT can more efficiently navigate this process. The study objective is not to change policy, but to help MDOT better work within the current system.

Progress:

Task C1 - Project Initiation - 100%. Project kickoff meeting was held with MDOT staff and consultant team on October 13, 2016. Task C2 - Literature Review - 100%. Reviewed relevant articles, reports and journals for literature review of past studies. Task C3 - 100%. Completed review of existing MDFA and MDOT State Management Plan for review and documentation of Federal/FTA requirements; TAC Meeting #1 was held on January 19, 2017. Task C4 – 100%. Completed survey of State DOTs; completed draft interim report. Task C5. – 40%. Initiated work on transit procurement recommendations.


Task C5 - subtask (a) - Continue work on transit procurement recommendations.

Task C5 - subtask (b) - Schedule TAC Meeting #2.

Task C6 - Initiate work on final report.


Employment Data for Gresham, Smith, and Partners Research Staff Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

5 4 1


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State Study No. 275— Intermodal Project Selection Criteria Principal Investigator: Ray Balentine MDOT Project Monitor: Cindy Smith

Funds Allocated: $94,612.00 Start Date: Awaiting NTP Expended to Date: $0 Completion Date: Awaiting NTP Research Agencies: Michael Baker Objective: MDOT seeks assistance with improving project selection criteria for the modal committees and other decision makers to use in allocating and distributing available project funds.


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State Study No. 276— Soil-Cement Manual of Practice: Interconnected Framework for Pavement Design, Laboratory Mixture Design, and Construction Quality Control/Assurance

Principal Investigator: Isaac Howard

MDOT Project Monitor: William F. Barstis, P.E. Funds Allocated: $350,000.00 Start Date: 9/20/2016 Expended to Date: $0 Completion Date: 12/31/2017 Research Agencies: Mississippi State University Objective: Develop a soil-cement manual of practice for MDOT that focuses on integrating pavement layer thickness design (MEPDG), laboratory mixture design, and construction quality control/assurance.

Progress:

Work was performed on three tasks.Task 2 saw 25% progress due to compaction delay efforts. Task 3 saw 15% progress due to density correction efforts. Task 5 saw 2.74111% progress due to field work.


Plans for the next quarter are to continue laboratory and field testing, literature review, and perhaps do a modest amount of analysis.



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State Study No. 277— Best Practices for Lighting and Marking Maintenance/ Construction Equipment for Safety

Principal Investigator: Tulio Sulbaran

MDOT Project Monitor: Alex Collum P.E. Funds Allocated: $150,000.00 Start Date: Waiting on NTP Expended to Date: $0 Completion Date: Waiting on NTP Research Agencies: University of Southern Mississippi Objective: MDOT seeks to improve the safety practices of lighting and marking vehicles and equipment to improve safety for its employees and contractors while on a jobsite. Improved lighting and marking on work vehicles and equipment should increase awareness of their presence to the travelling public. Employees’ lives are invaluable and putting the best resources towards protecting them is an easy decision. The findings from this study will allow MDOT to implement better standards for marking and lighting its own vehicle fleet as well as for contractor vehicles and equipment that is used on DOT projects. The goal of the improved standards is to make working on the roadways safer for everyone.


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State Study No. 278— Calibration Factors for Safety Performance Functions

Principal Investigator: TBD

MDOT Project Monitor: Alex Collum, P.E. Funds Allocated: $300,000.00 Start Date: TBD Expended to Date: $0 Completion Date: TBD Research Agencies: TBD Objective: Safety Performance Functions (SPFs) are equations that estimate expected average crash frequency as a function of traffic volume and roadway characteristics (e.g., number of lanes, median type, intersection control, number of approach legs). SPFs are developed through statistical regression modeling using historical crash data and are used to enable the correction of short-term crash counts. MDOT seeks to develop local calibration factors for the Safety Performance Functions used in the Highway Safety Manual (HSM) predictive method. SPF calibration factors tailored for the local conditions and crash frequency within Mississippi will help MDOT identify high-priority locations in which taxpayer dollars will be better utilized to keep the travelling public safe. The development of these SPF calibration factors will help better automate the crash prediction process within the Safety Analysis Management System (SAMS) program used by the MDOT Traffic Engineering Division. The SPF calibration factors will help MDOT prioritize the spending of approximately $35 million in Highway Safety Improvement Program (HSIP) funds annually.


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State Study No. 279— High Quality Simulation Training

Principal Investigator: Daniel Carruth

MDOT Project Monitor: Cindy Smith, P.E. Funds Allocated: $150,000.00 Start Date: Waiting on NTP Expended to Date: $0 Completion Date: Waiting on NTP Research Agencies: Mississippi State University Objective: Training for equipment operators and transit bus drivers is generally done on the job. Some agencies have begun using simulation training to teach new employees, as well as to train existing employees on new technology, for various types of equipment and buses. Simulation training is already used in aviation, marine transportation, and other industries. MDOT would like to begin looking at the use of simulators and virtual technology to train maintenance and transit staff by doing a synthesis research study. Maintenance simulation would initially focus on mowing because of the risk of turnover and training needed for new personnel to operate in the right-of-way. Transit simulation would focus on buses.


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State Study No. 281— Permeability Reduction of Restrained Concrete in a Chloride-Rich Environment

Principal Investigator: Robert Varner

MDOT Project Monitor: William F. Barstis, P.E. Funds Allocated: $350,000.00 Start Date: Waiting on NTP Expended to Date: $0 Completion Date: Waiting on NTP Research Agencies: Burns Cooley Dennis Inc. Objective: MDOT is now requiring waterproofing (permeability reducing) admixtures in bridge deck overlays in an effort to improve the long-term performance of bridges. These admixtures reportedly reduce permeability of concrete by plugging pores and capillaries throughout the entire mass of concrete. These admixtures react with water and cement hydration by-products to either formulate coalescing polymer globules or crystalline structures that seal pores, capillary tracts and micro cracks in hardened concrete. This makes hardened concrete less permeable to water and chemicals that corrode the reinforcing steel and create costly repairs. While some manufacturers note that these chemicals exceed performance requirements of industry standards such as ASTM C494 Type S, limited data is provided to document their performance in a bridge deck. Bridge structures create a restrained system for concrete shrinkage and many Mississippi bridges are exposed to chloride ions when salt is broadcast on the decks in winter months. This laboratory study will use testing equipment and chloride ion exposure to simulate these field conditions. Data compiled from this study will provide MDOT Engineers with information needed to verify that ordinary portland cement (OPC) or portland limestone cement (PLC) combined with these admixtures will reduce the permeability of portland cement concrete (PCC) in bridges. In addition, a testing protocol will be developed for MDOT to use for evaluating and approving future permeability reducing admixtures submitted to MDOT. This study will use forty-one laboratory mixtures to develop data to evaluate waterproofing admixtures that are currently approved for use on MDOT projects. Hardened concrete properties that will be evaluated include: 1) compressive strength; 2) restrained shrinkage cracking tendency; 3) chloride ion profile; 4) rapid chloride permeability; and 5) surface resistivity. The experimental mixtures will include Mississippi gravel aggregates and fine lightweight aggregate. The maximum nominal sizes of coarse aggregate will be No. 57 or No. 67 for bridge deck mixtures and No. 7, No. 78, or No. 8 for overlay mixtures. Mixtures will be developed with a blend of either


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OPC or PLC and supplementary cementitious materials (SCM’s) meeting the requirements of concrete mixtures for bridge decks and bridge deck overlays provided in special provision 907-804-20. Only one source of OPC, PLC, and SCMs will be utilized. Eighteen of these mixtures will focus on bridge deck overlays. The overlay mixtures will include compressive strengths ranging from 2,500 psi to 3,000 psi at 24 or 72 hours. The remaining twenty-three mixtures will meet requirements for bridge decks and will include both normal weight and lightweight fine aggregates for the purpose of internal curing.


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State Study No. 282— Traffic Signal Vehicle Detection, One Size Does Not Fit All

Principal Investigator: Waheed Uddin

MDOT Project Monitor: Marta Charria, P.E. Funds Allocated: $121,500.00 Start Date: 1/20/2017 Expended to Date: $0 Completion Date: 12/31/2018 Research Agencies: University of Mississippi Objective: This study will identify and establish a methodology to determine the most effective and economical type of vehicle detection at a signalized intersection. Since certain types can be more or less efficient depending upon traffic needs, environment, and geometry of the intersection.

For many years, MDOT’s standard practice has been the use of inductive wire loops. The life of detection loops are closely tied to the pavement performance, such that as the pavement fails, inductive loops also begin to fail. MDOT has been seeking non-intrusive detection types to replace inductive wire loops. So far MDOT uses several non-intrusive types besides of wire loops traffic signal detectors; however, there is not a defined procedure on how to select the most efficient and cost effective type. The study will provide MDOT with a standardized method for vehicle detection selection, allowing its staff to become more proficient in their effort to improve traffic operations and highway safety.

Progress:

1) Visit to the signal shop on April 14 to learn the basic operation of signal control box. 2) MDOT review of data collection form and a summary of candidate sites in Central, Southern, and Northern signal regions from the intersection lists provided by the MDOT signal engineers and more intersections added in Southern region. 3) Hands-on training of the project team at MDOT signal workshop and at a pilot field intersection site in Jackson area. 4) Data sets were collected at other selected intersection sites in Central signal region and three sites in Southern region.


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Work will continue as per the approved work plan tasks, as follows: 1) The project team will enter the collected data in Excel sheets (similar to the data collection form). 2) Revised plan for additional intersections in Southern signal region will be submitted for MDOT review. 3) Data collection on more intersections will be continued in Southern signal region.


Employment Data for University of Mississippi Total Male Female Staff White Black Hispanic Asian Native Am Arabic White Black Hispanic Asian NativeAm

5 4 1


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State Study No. 283— Adaptive Signal Performance Measures

Principal Investigator: Li Zhang

MDOT Project Monitor: Cindy Smith, P.E. Funds Allocated: $150,000.00 Start Date: Waiting on NTP Expended to Date: $0 Completion Date: Waiting on NTP Research Agencies: Mississippi State University Objective: MDOT seeks assistance to define performance measures that can be introduced into system specifications that will allow MDOT to measure the performance of its traffic signal systems. Data is continuously being collected along signalized corridors in the way of travel times (via Bluetooth readers) and traffic volumes. However, there is a need to be able to convert this big data into useful information. These performance measures, as monitored in periodically generated reports for certain periods of the day, will give indication of system deficiencies and failures which will allow MDOT to be proactive in addressing these issues and ultimately improve signal system operations.


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State Study No. 285— CSM Conversion Factors and Regression Parameters to Back Cast CSM Strength and Modulus

Principal Investigator: Isaac Howard

MDOT Project Monitor: Alex Middleton Funds Allocated: $150,000.00 Start Date: Waiting on NTP Expended to Date: $0 Completion Date: Waiting on NTP Research Agencies: Mississippi State University Objective: The AASHTOWare Pavement ME Design software requires a 28-day Modulus of Rupture (MOR) for characterizing the strength, and a 28-day elastic modulus (E) for characterizing the stiffness, of a cementitiously stabilized material (CSM) base layer. Cored field samples of CSM will be obtained as part of the data collection effort to locally calibrate the Pavement ME transfer functions. The age of these samples correspond to the period of time from initial construction to time of sampling; i.e., 10 – 20 years, not 28 days as required by Pavement ME. Further, Mississippi DOT has not evaluated the MOR for CSMs typically used in Mississippi. Since laboratory testing for CSM MOR is time consuming, level two correlation factors are required to estimate MOR from either CSM indirect tension (IDT) or unconfined compressive strength (UCS) tests.

In this study MOR, IDT, UCS, and E will be evaluated for typical Mississippi blends of CSM. Conversion factors will be developed between each of the three strength characterizations and between UCS and E. Strength and modulus regression parameters will be developed to back cast strength and modulus from age of cored samples to 28 days.

mississippi spr-1(103), p ii - mdot.ms.govmdot.ms.gov/documents/research/reports/progress reports/fy...

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