Abstract: The present invention provides an apparatus for forming concrete structures, such as railroad crossing signal foundations. The apparatus includes a generally hollow form, which is made from a strong and durable material, such as metal (e.g., steel) or composite material. The form is tapered and includes two halves that are selectively attached together for easy removal from a completed foundation. The form further includes several cantilever bolt holders that extend over the form and include holes that receive cantilever bolts that are incorporated into the foundation. One or more vibrating elements may be removably attached to the tops of the cantilever bolts and/or to the sides of the form. The air vibrators may be selectively activated during the cement pouring process to vibrate the concrete and substantially reduce or eliminate air bubbles and defects within the foundation. A pair of adjustable legs is attached to the form and allows the form to be positioned and supported over a foundation hole.