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Project Details
STATUS

In-Progress

PROJECT NUMBER

21-772

START DATE

09/15/21

END DATE

10/31/23

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Jeramy Ashlock

Faculty Affiliate

About the research

The previous IHRB project, TR-685: Feasibility of Granular Road and Shoulder Recycling, involved construction and testing of several granular road and shoulder test sections in which existing surface materials were recycled and blended with virgin materials. One of the most useful outcomes of the TR-685 Phase I project is the Gradation Optimization tool, a spreadsheet that allows engineers to determine the optimum mixture of existing granular surface materials with up to three virgin quarry materials (along with a selected thickness of subgrade for plasticity if desired).

This project will be a Phase II follow-on to TR-685, with a project goal of expanding the accuracy of the Gradation Optimization tool by more extensive testing of a wider range of material types and material blends. The representative surfacing aggregates will be collected from quarries across Iowa. The material types will include crushed river gravel, higher strength limestone, and various others typically used for granular surfaces in different regions of Iowa.

Project Details
STATUS

In-Progress

PROJECT NUMBER

21-767

START DATE

07/01/21

END DATE

08/31/21

SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Skylar Knickerbocker

Research Engineer, REACTOR

Co-Principal Investigator
Neal Hawkins

Associate Director, InTrans

About the research

This grant will support the establishment of an Iowa Department of Transportation (DOT) WZDx-compliant data feed. The feed will be integrated into the statewide Advanced Traffic Management System (ATMS) and populated with the Institute for Transportation’s new and improved Work Zone Data Initiative (WZDI), which uses data from smart arrow boards statewide to automate how work zone time and location information is updated.

The Iowa DOT relies on their 511 website to communicate with the public. Data typically follows the Traffic Management Data Dictionary (TMDD) standard, which lacks the details necessary for work zones, thus leading to the need for WZDx.The information within most DOT 511 websites is often an inaccurate representation of the work zone in the field due to several factors, including the required manual input of data from field staff and TMC operators.

Project Details
STATUS

In-Progress

PROJECT NUMBER

21-769

START DATE

07/15/21

END DATE

12/31/21

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Nicole Oneyear

Associate Scientist, CTRE

Co-Principal Investigator
Shauna Hallmark

Director, InTrans

Co-Principal Investigator
Hossein Naraghi

Research Scientist, CTRE

About the research

In response to the proposed Baylee’s Bill in the Iowa Legislature, the Iowa Department of Transportation (DOT) was charged through HSB 711 with studying “the effectiveness of rumble strips in preventing vehicle crashes at certain stop-controlled intersections as determined by the department.” The Iowa DOT requested that the Institute for Transportation provide support in accomplishing this.

The following are the project objectives:

  1. Summarize the effectiveness of Transverse Rumble Strips (TRS) at stop-controlled intersections based on current literature
  2. Document the practices of other State DOT’s related to the application of TRS at stop-controlled intersections
  3. Provide cost estimates and benefit cost ratios for various scenarios of TRS implementation in Iowa
Project Details
STATUS

In-Progress

PROJECT NUMBER

21-773

START DATE

08/15/21

END DATE

08/14/22

RESEARCH CENTERS InTrans
SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Hantang Qin
Co-Principal Investigator
Juan Ren

About the research

Work completed under this project will help Iowa Department of Transportation (DOT) decision makers better analyze and communicate results using data driven approaches. Some of the methods for this work can involve advanced analytics and data visualization techniques. These methods will help in developing the approach to improve decision making across asset resource allocation. The work under this project will provide an opportunity to change some of the existing approaches and give insights into how the new approaches can be implemented. The benefits have the potential to impact multiple assets across the transportation agency.

Project Details
STATUS

In-Progress

PROJECT NUMBER

21-760

START DATE

05/01/20

END DATE

06/30/21

SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Zachary Hans

Director, CWIMS

Co-Principal Investigator
Skylar Knickerbocker

Research Engineer, REACTOR

Co-Principal Investigator
Nicole Oneyear

Associate Scientist, CTRE

About the research

The Iowa DOT Work Zone GO Team is a focused effort to reduce fatal and major injury crashes within work zones on the primary highway system in Iowa. The Iowa Department of Transportation has requested that the Institute for Transportation provide support to the team through acquisition, assimilation, and review of pertinent work zone, crash, and situational data.

Work includes InTrans FY21 Work Zone GO Team support efforts, which focus on: (1) establishing the contextual data needed to support these efforts, and (2) beginning to produce the information for review and refinement. Support may include associating work zone crashes with construction and maintenance actions, construction project numbers, the traffic control used, as well as other potentially useful data, such as traffic speed, volume, and weather conditions.

Project Details
STATUS

In-Progress

PROJECT NUMBER

21-763, TR-796

START DATE

08/01/21

END DATE

07/31/23

RESEARCH CENTERS InTrans, PROSPER
SPONSORS

Iowa Department of Transportation
Iowa Highway Research Board

Researchers
Principal Investigator
Halil Ceylan

Director, PROSPER

Co-Principal Investigator
Sunghwan Kim

Associate Director, PROSPER

Co-Principal Investigator
Masrur Mahedi

About the research

Over 71,000 miles (i.e., over 75%) of county roads in Iowa are granular (unpaved) roads. Iowa granular roads carry low daily traffic volumes (i.e., 10 to 200 vehicles/trucks per day) yet frequently support heavy vehicle (e.g., farm equipment) movements. According to a recent estimate, Iowa’s county road departments spend over $145 million annually on maintenance costs, which predominantly includes over $35 million for blading and over $110 million for resurfacing. In addition, a wide range in granular material quality, supply, and price available in different regions of the state results in significant differences in the level-of-service. Therefore, Iowa county engineers have a specific set of criteria based on their own experiences when designing and managing granular roads. Considering the lack of granular road structural design standards to meet Iowa county engineers’ requirements for current granular road management practices, significant research is needed to develop a comprehensive but practical structural design tool for cost-effective design and construction of local granular road systems in Iowa.

The primary objective of this study is to meet such research needs. This will be achieved through the execution of five concurrent research studies: (1) surveys/interviews, forensic investigations, and laboratory tests to identify the best practices for Iowa granular roads around the state; (2) construction, instrumentation, and performance monitoring of field demonstration sites; (3) development of deterioration prediction models subjected to Iowa granular roadways; (4) cost-effectiveness analysis; and (5) development of a structural design tool and additional guidance documents. The outcomes of this research will substantially improve overall performance, save on maintenance and operation costs, and enhance the safety and mobility of Iowa granular roads by addressing key performance indicators (e.g., drainage, cross-slope, aggregate loss, and freeze/thaw susceptibility) through the granular road design procedure.

Project Details
STATUS

Completed

PROJECT NUMBER

18-640, TR-740

START DATE

01/01/18

END DATE

06/30/21

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, PROSPER
SPONSORS

Iowa Department of Transportation
Iowa Highway Research Board

Researchers
Principal Investigator
Halil Ceylan

Director, PROSPER

Co-Principal Investigator
Sunghwan Kim

Associate Director, PROSPER

Co-Principal Investigator
Danny Waid

Iowa County Engineers Service Bureau

Co-Principal Investigator
Brian Moore

Iowa County Engineers Service Bureau

About the research

Recent federal legislation requires state highway agencies (SHA) and local road agencies to utilize performance-based approaches in their pavement management decision-making processes. The use of a remaining service life (RSL) model would be one such performance-based approach that could facilitate the pavement management decision-making process.

This study developed a Microsoft Excel macro and Visual Basic for Applications (VBA)-based Iowa Pavement Analysis Techniques (IPAT) automation tool that Iowa county engineers can use to estimate the project- and network-level pavement performance and RSL. To address this aim, statistics and artificial neural network (ANN)-based pavement performance and RSL models were developed using pavement structural features, traffic, construction history, and pavement performance records obtained from the Iowa Department of Transportation (DOT) Pavement Management Information System (PMIS) and the Iowa county agencies’ database. The accuracy of models was evaluated using real database representing Iowa county pavement systems.

The IPAT tool provides a series of options for four pavement types representing Iowa county pavement systems—jointed plain concrete pavement (JPCP), asphalt concrete (AC) pavement, AC over JPCP, and portland cement concrete (PCC) overlay—to estimate RSL through different approaches based on various conditions and distress data availability from an individual county. As part of data processing, the concept of developing an Iowa historical performance databank (HPD) was introduced and demonstrated by using raw data collected from county pavements. In addition, the feasibility of integrating preservation and rehabilitation techniques for RSL predictions using ANN models was investigated to evaluate the effects of treatments on RSL of pavements.

The IPAT tool is expected to be used as part of performance-based pavement management strategies and to significantly help decision-makers facilitating maintenance and rehabilitation decisions for better prioritization and allocation of resources.

Project Details
STATUS

Completed

PROJECT NUMBER

19-691, 19-SPR2-001, ABC-UTC-2016-C3-ISU02-Final

START DATE

04/15/19

END DATE

06/24/21

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC
Iowa Department of Transportation

Researchers
Principal Investigator
Katelyn Freeseman

Acting Director, BEC

About the research

Lateral slidein bridge construction (SIBC) has gained increasing attention as a viable accelerated bridge construction (ABC) approach. With lateral slide construction, the majority of the bridge superstructure is constructed off alignment, typically parallel to the final position, and usually on a system of temporary works.

While many state departments of transportation (DOTs) have completed lateral slide construction of singlespan bridges and have common connection details already established, these details do not directly apply to multispan slides. The addition of more spans creates a more complex system that require connections (and other details) that were previously not needed in a singlespan slide. In addition, the fact that the multispan bridge needs to slide on abutments plus piers (as opposed to just abutments) creates possible uplift and overturning scenarios.

A comprehensive literature search was conducted to find relevant information on the implementation of SIBC on multispan bridges. However, limited public information was found that directly related to the substructure behavior subject to the lateral slide load. An analytical simulation was conducted to investigate the structural behavior of the bridge piers during the bridge slidein and to evaluate the drawbacks and advantages of two and fourpoint pushing.

A finite element (FE) model was developed and validated against the data collected from a field monitored bridge. The results indicated that twopoint pushing increases the loading on the pier diaphragm by 36%. Because of this, the pier response with respect to the tilt about the x and z directions increased; however, this increase was not significant. By analyzing the field and analytical solution results, it was also found that the bridge pier experienced a greater rotation about the bridge transverse direction than about the longitudinal direction.

The results of the FE modeling and the literature search resulted in unanswered questions that would benefit from further study. A detailed research plan including a series of laboratory tests is presented in the Phase I report.

Project Details
STATUS

In-Progress

PROJECT NUMBER

20-744

START DATE

07/01/20

END DATE

12/31/21

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Hossein Naraghi

Research Scientist, CTRE

Co-Principal Investigator
Zachary Hans

Director, CWIMS

About the research

Iowa has a long history of converting two-lane and four-lane roadways to a three-lane cross section consisting of a through lane in each direction of travel and a center two-way left turn lane (TWLTL) for safety purposes. Several notable studies were conducted in Iowa in the early 2000s demonstrating the safety effectiveness of such conversions as well as offering guidance for conversion. These studies also suggested possible greater safety impacts compared to other contemporary studies.

Several different roadway and roadside characteristics may impact the possible effectiveness of three-lane cross sections. Some of these characteristics are collected and maintained by the Iowa Department of Transportation (DOT) through the Roadway Asset Management System (RAMS) (and formerly Geographic Information Management System [GIMS]). However, accuracy issues have been found to exist with some of these characteristics, including the presence of a TWLTL, due to the frequency of update and reliance on agency reporting. Additionally, several other characteristics that may potentially impact safety and/or operations have not been traditionally inventoried.

The primary objectives of this project are to identify three-lane roadways throughout the State of Iowa and collect (or update) pertinent roadway and roadside characteristics. Emphasis will be on current characteristics but may extend to historic characteristics, where available. Furthermore, relevant crash experience along the identified three-lane roadways will be captured for future safety analysis. Documenting the history and characteristics of three-lane sections will facilitate evaluation of the safety and/or operational-related impacts of these roadways. It will also allow for identification of common characteristics of well-performing, existing sites and similarities between them and potential three-lane conversion sites.

Project Details
STATUS

In-Progress

PROJECT NUMBER

21-758

START DATE

05/01/21

END DATE

04/30/22

RESEARCH CENTERS InTrans, CMAT
SPONSORS

Iowa Department of Transportation

Researchers
Principal Investigator
Ronald Cox

About the research

Iowa State University’s Center for Industrial Research and Service (CIRAS) will provide support services to DBE businesses in Iowa with the goal of increasing their overall participation in Iowa Department of Transportation (DOT) let projects. CIRAS will leverage existing partnerships and programs to increase awareness of the DBE/SS program and leverage other federal programs such as the Procurement Technical Assistance Program (PTAP) and Small Business Development Center (SBDC) to provide needed services to DBEs.

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