Specifications include, but are not limited to: This Request for Expressions of Interest (“RFEI”) is issued to invite interested vendors to help the New York City Department of Transportation (“NYC DOT” or “DOT”) conduct an evaluation of solarpowered real-time passenger information sign technologies (“solar RTPI signs”). These solar-powered signs will visually display real-time bus arrival information at bus stops in NYC without requiring a wired power or data connection, and will contain an audible announcement component. Secondarily, DOT is interested in evaluating new designs for wired RTPI sign technologies which could be paired with the solar designs. NYC DOT seeks effective technology and system approaches from interested firms that would accomplish these goals, taking into account the demanding New York City operating environment.