System-Based Safety Tenets Applied to the Extra-High Voltage Transmission Line Design for Common Uses of Highway Right-of-Way

The rapidly increasing demand for electricity in recent years resulted in increasing needs of electrical system capacity and deployment for alternate uses of highway right-of-way (ROW) for the purpose of electric power generation, transmission, and distribution. In this framework, a systems approach—fundamental principles of system dynamics for identifying, understanding, and analyzing safety requirements of the extra-high voltage power line (EHV)—is used to objectively focus on two main safety issues related to the design and the risk of the EHV transmission line within highway ROW: (1) assess the design and the operation, and (2) evaluate causally related impacts on the public and workers’ safety that matter. A generalized model of the electromagnetic fields distribution and the clearance model are developed for the analysis of the causally related impacts of a conceptual design and the reliability of materials of construction of the electric systems by introducing the number of exposed individuals and the level of the environmental impacts as a second dimension in addition to the risk factors. A worst-case design scenario is evaluated. Sensitivity analysis of effects of the design attributes such as the route configuration, over voltages, and conductor clearance is performed by determining the magnitude of the electromagnetic field strengths and predicting the resulting maximum voltage. Information obtained on the structural design scenario, conductor size and configuration, insulators, and connectors is of value in determining the safety of the design for operation at extra-high voltages within highway ROW.