Work Zone Safety Analysis, Investigating Benefits from Accelerated Bridge Construction (ABC) on Roadway Safety

Link to the Latest: September 2020 Progress Report

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Background:
Due to the growth of highway renovations and construction projects in the state of Florida, the number of work zones has increased. Work zones create traffic congestion and the attributes of work zones have significant impacts on the risk of crash occurrence. According to statistics from the American Road and Transportation Builders Association (ARTBA), Florida is among the top three states for work zone fatal crashes with a total of 73 fatal crashes causing resulting in 80 fatalities in 2016. Work zone crashes constitute approximately 1.6% of the total crashes (i.e., 712,177), with 3,186 injury crashes in 2016 in Florida (S4A). Another important aspect of work zone crashes which needs to be considered by decision-makers, is worker safety. Among the total number of work zone crashes in 2016 in the state of Florida, around 44.8% were associated with worker presence, in which 12 workers were killed. The worker fatalities in 2016 are 9.1% and 57.1% higher compared to 2015 and 2014, respectively (ARTBA). The significant loss of workers’ lives and injuries resulting from work zone crashes indicates the emergent need of a comprehensive and in-depth investigation of work zone crash mechanisms. The cost of work zone crashes is another issue that should be taken into account as the work zone crashes impose millions of dollars on society each year. It can be argued that as traffic volume continues to increase, so will work zones. Hence, it is necessary to investigate the possible causes associated to crash severity and frequency to improve work zone safety.

According to Manual on Uniform Traffic Control Devices (MUTCD), bridge construction/reconstruction is categorized as long-term stationary work zones since the construction duration is basically over three days. This long roadway occupancy and its related components such as lane closures, lane width reductions, changes in road geometry, and the presence of construction workers increase the crash occurrence risk. According to a recent review from Yang et al. (2015) on work zone safety analysis and modeling, over 85% of previous studies regarding work zone crash frequency demonstrate an obvious increase in crash frequencies during work zone operations. Applying innovative construction methods like Accelerated Bridge Construction (ABC) dramatically decreases onsite construction duration, thus improve roadway safety. This safe and cost-effective procedure for building new bridges or replacing or rehabilitating existing bridges in just a few weeks instead of months to years not only saves a lot of crash costs but people’s lives. However, so far, there is no such study that assesses the roadway safety enhancement aspect of ABC implementation method. In addition, most of the existing safety research has focused on the traveling public and not on worker safety.

Objective:
This project aims to identify the contributing factors that affect crash frequency and crash severity of work zone crashes through the conjunction of the results from conventional statistical models and machine learning techniques. This can provide a more comprehensive interpretation of work zone crash severity and frequency outcomes. The analysis sheds light on the internal probability patterns of crash contributing factors, as well as their overall impacts. In addition, it seeks to assess the impact of ABC implementation to enhance work zone safety through a benefit-cost analysis, which has not been investigated and documented yet.

Scope:
This project focuses on the development of simulation technique targeted at bridge demolition. The following tasks will be performed to achieve the project objective:

  • Task 1 – Literature Review
    • This project will first perform a comprehensive review of the literature on construction work-zone crash analysis.
  • Task 2 – Descriptive Analysis
    • Provide a detailed descriptive analysis of crash data with a focus on work zones in Miami-Dade County.
  • Task 3 – Crash Severity Analysis
    • Crash severity analysis through logistic regression and machine learning techniques will be conducted.
  • Task 4 – Crash Frequency Analysis
    • Crash frequency analysis through logistic regression and machine learning techniques will be conducted.
  • Task 5 – Benefit-Cost Analysis
    • Evaluate the costs associated with crash occurrence and crash severity in work zone locations. Then, the benefits of ABC implementation through a monetary assessment of the potential avoided crashes to support the decision-making process of highway construction projects. Besides, the ABC method will be evaluated if it brings more benefits than it costs in the project life-cycle.

Research Team:
Principal Investigator: Dr. Islam Mantawy
Project Consultant: Dr. Atorod Azizinamini
Research Assistant: Seyedmirsajad Mokhtarimousavi, PhD Candidate

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