Since
September 2017, the first four on-ramp signals in North Carolina, positioned on
the westbound lanes of I-540 in Wake County, have been regularly activated
Monday to Friday from 6:30 - 9am. This report focused
on the impact of these on-ramp signals. The results identified are the product
of data collected in the I-540 WB area over multiple years from numerous
sources, both before and after on-ramp signals. When feasible, the costs and
benefits of the on-ramp signals were monetized using benefit cost analysis
methods. The results of this study show that the on-ramp signals resulted in
benefits including a forecasted net savings of $7,949,541 over the ten years after the
installation of the on-ramp signals. In addition, the analytical methods updated and
developed through this study will provide NCDOT with planning and evaluation
frameworks that can be readily applied to future on-ramp signal projects. In
the future, NCDOT can use the planning-level tools to evaluate the potential of
implementing on-ramp signals in other locations in the state and can apply the
evaluation tools to assess the impacts of the on-ramp signals after
installation. Ultimately,
the methods, processes, and lessons learned delivered with this study can help
North Carolina save make faster and more accurate decisions about future
on-ramp signal projects.
