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Project Details
STATUS

Completed

START DATE

05/15/16

END DATE

11/30/18

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE, MTC
SPONSORS

Michigan Department of Transportation
Midwest Transportation Center
USDOT/OST-R

Researchers
Principal Investigator
Peter Savolainen

Affiliate Researcher

Co-Principal Investigator
Timothy Gates
Student Researcher(s)
Raha Hamzeie
Trevor J. Kirsch
Qiuqi Cai

About the research

The relationship between speed and safety continues to be a high-priority research topic as numerous states consider speed limit increases. This study leveraged data from the Second Strategic Highway Research Program (SHRP2) Naturalistic Driving Study (NDS) to examine various aspects of driver behavior, including speed limit selection and engagement with in-vehicle distractions, as well as the impacts of these behaviors on crash risk while controlling for the effects of traffic, geometric, and environmental conditions. High-resolution time-series data were analyzed to examine how drivers adapt their speed on roadways with different posted limits, in speed limit transition areas where increases or decreases occur, as well as along horizontal curves, both with and without posted advisory speeds.
The research also involved an investigation of the circumstances under which driver distraction is most prevalent. The factors associated with crash and near-crash events were compared with similar data from normal, baseline driving events across various scenarios to improve understanding of the nature of the precipitating events. Driver responses, including reaction times and deceleration rates, were examined during the course of crash and near-crash events to determine how driver response varied across various scenarios.
Ultimately, this research provided important insights as to how drivers adapt their behavior and how these behaviors, in turn, influence the likelihood of being crash involved.


Funding Sources:
Midwest Transportation Center
USDOT/OST-R ($50,000.00)
Total: $50,000.00

Contract Number: DTRT13-G-UTC37

Project Details
STATUS

In-Progress

START DATE

10/01/15

END DATE

03/31/18

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Michigan Department of Transportation

Researchers
Principal Investigator
Peter Savolainen

Affiliate Researcher

About the research

This research aims to develop a uniform, consistent approach that can be applied to estimate the safety performance of rural intersections and road segments at the aggregate (i.e., total crash) level, as well as within specific crash types and crash severity categories. The study results will provide important guidance for the Michigan Department of Transportation (DOT) and local road agencies to make informed decisions as to safety projects.

The Institute for Transporation is a subcontractor to Michigan State University (MSU) on this project.

 

Project Details
STATUS

In-Progress

START DATE

07/01/14

END DATE

04/30/15

RESEARCH CENTERS InTrans
SPONSORS

Michigan Department of Transportation

PARTNERS

Wayne State

Researchers
Principal Investigator
Peter Savolainen

Affiliate Researcher

About the research

Ultimately, the study results will provide important guidance to allow the Michigan Department of Transportation and the state to make informed decisions as to potential changes in the state’s speed limit policies.

Project Details
STATUS

Completed

START DATE

08/16/15

END DATE

07/31/16

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Federal Highway Administration State Planning and Research Funding
Michigan Department of Transportation

Researchers
Co-Principal Investigator
Peter Savolainen

Affiliate Researcher

About the research

This study involved the development of safety performance functions (SPFs) for signalized and stop-controlled intersections located along urban and suburban arterials in Michigan. Extensive databases were developed that resulted in the integration of traffic crash information, traffic volumes, and roadway geometry information.

After these data were assembled, an exploratory analysis of the data was conducted to identify general crash trends. This included assessment of the base models provided in the Highway Safety Manual (HSM), as well as a calibration exercise, which demonstrated significant variability in terms of the goodness-of-fit of the HSM models across various site types.

Michigan-specific SPFs were estimated, including simple models that consider only annual average daily traffic (AADT). More detailed models were also developed, which considered additional geometric factors, such as posted speed limits, number of lanes, and the presence of medians, intersection lighting, and right-turn-on-red prohibition.

Crash modification factors (CMFs) were also estimated, which can be used to adjust the SPFs to account for differences related to these factors. Separate SPFs were estimated for intersections of only two-way streets and for those where at least one of the intersecting streets was one-way, as the factors affecting traffic safety were found to vary between these site types.

Severity distribution functions (SDFs) were also estimated, which can be used to predict the proportion of injury crashes that result in different injury severity levels. The SDFs may include various geometric, operation, and traffic variables that will allow the estimated proportion to be specific to an individual intersection.

Ultimately, the results of this study provide the Michigan Department of Transportation (MDOT) with a number of methodological tools that will allow for proactive safety planning activities, including network screening and identification of high-risk sites. These tools have been calibrated such that they can be applied at either the statewide level or within any of MDOT’s seven geographic regions, providing additional flexibility to accommodate unique differences across the state.

The final report also documents procedures to maintain and calibrate these SPFs over time, allowing for consideration of general trends that are not directly reflected by the predictor variables.

 

Project Details
STATUS

Completed

START DATE

02/01/03

END DATE

12/01/07

RESEARCH CENTERS InTrans, CP Tech Center, CTRE
SPONSORS

American Concrete Pavement Association
Concrete paving industry
Federal Highway Administration
Georgia Department of Transportation
Indiana Department of Transportation
Iowa Department of Transportation
Kansas Department of Transportation
Lousiana Department of Transportation
Michigan Department of Transportation
Minnesota Department of Transportation
Nebraska Department of Roads
New York State Department of Transportation
North Carolina Department of Transportation
North Dakota Department of Transportation
Ohio Department of Transportation
Oklahoma Department of Transportation
South Dakota Department of Transportation
Texas Department of Transportation
Wisconsin Department of Transportation

Researchers
Principal Investigator
Jim Grove

PCC Engineer

Co-Principal Investigator
Tom Cackler
Student Researcher(s)
Fatih Bektas

About the research

The objectives of this five-year Transportation Pooled Fund study are to evaluate conventional and new technologies and procedures for testing concrete and concrete materials to prevent material and construction problems that could lead to premature concrete pavement distress, and to develop a suite of tests that provides a comprehensive method of ensuring long-term pavement performance. A preliminary suite of tests to ensure long-term pavement performance has been developed. Shadow construction projects are being conducted to evaluate the preliminary suite of tests. A mobile concrete testing laboratory has been designed and equipped to facilitate the shadow projects. The results of the project are being compiled in a user-friendly field manual, which will be available by summer 2006.

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