Recent studies indicate that work zones suffer from an increasing trend of deaths and injuries in and around the highway construction areas with an average of 745 fatalities and 40,700 severe injuries per year. To control and minimize work zone fatalities and injuries, the Federal Highway Administration (FHWA), American Association of State Highway and Transportation Officials (AASHTO), and many state Departments of Transportation (DOTs) are seeking to improve the design practices of work zones to reduce work zone crashes. To support this vital and pressing highway safety goal, this research study focuses on analysing and optimising existing work zone practices and exploring the effectiveness and efficiency of innovative temporary rumble strips that can be used to minimize crashes in and around highway construction and maintenance projects. The research objectives of this study are to: (1) provide enhanced understanding of the impact of work zone parameters and innovative temporary traffic control devices on the safety of highway construction zones; (2) analyse work zone crashes and current practices to identify potential layout parameters that impact work zone crash occurrence; (3) investigate and quantify the impact of work zone layout parameters on the risk and cost of crash occurrence; (4) optimise work zone setup parameters to minimize total work zone costs including agency, user delay, and expected crash costs; (5) conduct field experiments to analyse the efficiency and constructability of various arrangements of temporary rumble strips prior to and at the edge of work zones; and (6) study and enhance the effectiveness of temporary rumble strips in alerting inattentive drivers prior to and at the edge of work zones. In order to achieve these objectives, the study is conducted in seven major tasks that focus on: (1) conducting a comprehensive literature review; (2) collecting and fusing all available data and reports on work zone crashes in Illinois; (3) analysing work zone crashes and identifying the probable causes and contributing factors; (4) identifying the impact of layout parameters on risk of crash occurrence; (5) developing an optimisation model to minimize total work zone costs including agency cost, user delay cost, and expected work zone crash cost; (6) performing field experiments on temporary rumble strips and evaluate the efficiency of utilization on site; and (7) evaluating the effectiveness of temporary rumble strips prior and at the edge of work zones. The main research developments of this study are expected to have significant impacts on (1) identifying potential work zone parameters and contributing causes that impact work zone crash occurrence; (2) estimating the probability of work zones to encounter severe crashes; (3) quantifying the impact of work zone parameters on the risk levels of crash occurrence; (4) estimating the monetary value of work zone crashes based on work zone layout parameters; (5) searching for and identifying optimal work zone setup solutions that specify segment length, operating speed, TTC policy, and concrete barrier at different operation staring times; (6) developing new efficient prototypes of temporary rumble strips to be utilized prior to and at the edge of work zones; and (7) developing practical guidelines for effective design arrangements of temporary rumble strips. These new developments hold a strong promise to: (a) improve work zone safety for both the travelling public and construction workers; (b) improve current work zone layouts, strategies, and standards; (c) provide a baseline for controlling the risk of crash occurrence due to highway work zones; (d) assist construction planners in identifying optimal work zone setups for highway construction; (e) direct the development of practical recommendations for efficient and effective design arrangements of temporary rumble strips; and (f) reduce work zone crashes in the work area through the implementation of practical temporary rumble strips arrangements. (Author/publisher)
Abstract