A project testing the mechanical and operational reliability of electrically actuated drop-arm style closure gates is needed to determine if this type of gate would be a superior design when compared to the existing manual swing style gates. ThomTech Designs, Inc. has an actuator system that is used to retrofit drop-arm style gates. The system attaches to the existing gate assembly and replaces the manual hand winch used to raise and lower the arm with an electric linear actuator. The system also includes a wireless switch kit to activate advanced warning flashing lights and a handheld remote control device programmed to operate the individual gates and the advanced warning light system. It is proposed to install actuators on the gates that will be installed on the eastbound gates of Interstate 90, Exit 67, Project IM-P-90-2(71)66.
The needs assessment portion of the research project will focus on determining the appropriate configuration for a gate system at the existing sites statewide. While reviewing the site configuration, the benefit of automation will be evaluated. Automation of road closure gates could range from simple handheld remote control units that could be operated from a vehicle to sophisticated systems including Internet control of gate operations, advanced warning signs and real time video cameras.
Findings: Nearly all of South Dakota's road closure gates were installed in the early 1980's and few modifications have occurred to the gates since the original installations. This study examined possible changes to South Dakota road closure gates, including ways that automated features might be incorporated to make intended functionality more amenable. The ultimate goals of the project were to improve road closure gate operations and minimize the safety concerns for SDDOT maintenance personnel at road closure sites. The study required an overall assessment of road closure sites around the state to determine the performance issues surrounding existing gate configurations. The study then proceeded to relate what types of modifications might be warranted at each of the various sites, along with an assessment as to the extents that automation might be introduced.
Reviews of literature focusing on state-of-the-art road closure equipment, various methodologies to perform road closures, and the dictates that frame the performance of road closures resulted in the accumulation of a variety of material on the subject. The research efforts to perform detailed assessments of road closure sites on a statewide basis were performed through in-depth surveys of maintenance personnel at SDDOT Area Offices. Other information was gathered through on-site visits to road closure locations both in-, and out of the state. To facilitate the analysis efforts of the automated aspects, an actual installation of electrically actuated drop-arm style gates was performed for testing and evaluation purposes. The "test installation" was meant to evaluate the reliability of the design, mechanical, and operational characteristics of this type gate in comparison to similar characteristics found in South Dakota's existing swing-type gates.
The investigations of South Dakota's existing road closure gate systems and their functional performance led to conclusions that the currently used gates do need to be replaced. However, the history collected on the existing gates frequency of use turned out to be a primary piece of evidence that indicated the gate replacement alternatives should not include very high costs, be greatly sophisticated, or include very extensive levels of automation. Study findings eventually led to conclusions that the implementation of basic, low cost equipment configurations at South Dakota road closure sites would be the best overall approach. Recommendations for alternative site treatments at the various road closure locations are based on criteria that strongly evidenced this strategy. However, research findings also indicated the SDDOT will need to ensure that applicable laws, policies, and procedural definitions for the performance of road closures in the state are closely adhered to during the implementation efforts.