Retroreflective traffic signal backplates are designed to increase the visibility of traffic signals (particularly at night) and are a simple, inexpensive countermeasure that can reduce crashes by improving driver awareness of traffic signals. The Connecticut Department of Transportation will be installing the backplates on all traffic signals that are being upgraded in projects.
See the attached link for more information on retroreflective traffic signal backplates: Retroreflective Traffic Signal Backplates