Missouri Systemic Countermeasures to Improve Pedestrian Safety

Missouri Department of Transportation (MoDOT) has successfully implemented systemic safety countermeasures in the past to reduce fatal and serious injury crashes related to roadway departure. MoDOT initiated this research project to address the increasing trend in pedestrian fatalities and serious injuries in Missouri. The focus of the project is to develop a Missouri Pedestrian Safety Countermeasure Tool based on analysis of pedestrian-involved crash data and identification of situational trends. This matrix-based tool identifies those peer groups (segments and intersections) that have the highest risk of pedestrian crashes and the countermeasures based on a particular set of roadway criteria (traffic volume, speed limit, and number of lanes) that can be applied across various jurisdictions. The Pedestrian Safety Countermeasure Tool includes multiple peer groups for road segments, signalized intersections, and unsignalized intersections. Overall, the study found that several priority peer groups provide the greatest impact for reducing pedestrian crashes through implementation of the Pedestrian Safety Countermeasure Tool. GIS maps were developed for each Metropolitan Planning Organization (MPO) area to facilitate implementation. Modifications to policies can further enhance pedestrian safety in Missouri.

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Report number: cmr 22-013
Published: November 2022
Project number: TR202010a
Authors: Priscilla Tobias, Timothy Szwedo, and Brady Nye 

Performing organization: Arora and Associates, P.C.

Implementation of Data Quality Assurance (QA) for Innovative Technologies at MoDOT

Intelligent construction technologies (ICTs) combine modern science and innovative construction technologies. The goal of ICT is to improve the quality of construction, save costs, and improve safety. The ICTs described in this report include intelligent compaction (IC), paver-mounted thermal profiler (PMTP) equipment, and dielectric profiling systems (DPS). IC and PMTP systems are mounted on contractor paving equipment. Therefore, the data generated by these systems is collected by the contractor. DPS systems can be owned and operated by the agency or contractor.

Meeting the Code of Federal Regulations (CFRs) for construction acceptance using ICT is a national issue but a worthwhile endeavor to ensure the ICT produces quality data for construction acceptance decisions. MoDOT is among the leading DOTs working towards satisfying the requirements to implement ICT. This project's main objective is to advance MoDOT's efforts to obtain data QA solutions for ICT.

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Report number: cmr 22-012
Published: November 2022
Project number: TR202124
Authors: Dr. George Chang, Amanda Gilliland, and Dr. Abbas TaghaviGhalesari 

Performing organization: The Transtec Group, Inc.

Implementing the LWD for MoDOT Construction Acceptance of Unbound Material Layers

Conventional density-based methods of compaction quality assurance (QA) using nuclear density gauges (NDG) have been the practice for many years. However, NDG testing becomes less desirable because of safety, regulatory, and cost concerns. In addition, density is not a direct input to the structural design of the pavements and is not directly linked to pavement performance.

In recent years, modulus-based compaction QA of unbound materials is gaining attention, as it can not only result in a better constructed product but also provide the engineering properties critical for better understanding of the connection between pavement design and long-term pavement performance. Moisture content is one of the main factors influencing soil modulus and should also be performed concurrent with field modulus measurement. However, existing LWDs do not have the function to measure moisture content. 

In this study, a national survey on acceptance of LWD and a substantial literature review were firstly carried out to study the current status of LWD application. Then, four types of representative soils from two projects provided by MoDOT were selected to investigate the implementation of LWD for construction acceptance of unbound materials. Four LWD devices including three Zorn ZFG 2000 and one Zorn ZFG lab 3.0, were used in laboratory and field tests. Furthermore, two moisture content analyzers including Aggrameter and Ohaus MB120 were chosen to evaluate their practicability of quick moisture content measurement in the field. Based on the results of considerable laboratory and field tests, it was concluded that the modulus-based construction quality assessment method using LWD and moisture content analyzer Ohaus MB120 worked well at four construction sites. In addition, a guideline was created for the use of the modulus-based method in the appendix. 

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Report number: cmr 22-011
Published: November 2022
Project number: TR202103
Authors: Xiong Zhang, Jenny Liu, Beshoy Riad, and Chuanjun Liu

Performing organization: Missouri University of Science & Technology