A rail brace assembly provides positive support for a stock rail mounted on a switch brace plate. The assembly includes a rail brace having a generally central opening that it is installed over a fixed clip housing attached to the brace plate. The clip housing accepts a resilient clip that secures the rail brace in position on the brace plate and against the stock rail. The resilient clip provides spring force directly to the rail brace in both a vertically downward direction and a lateral direction. The rail brace has a lug to prevent the clip from being removed from the clip housing due to vibration. The clip housing prevents the brace from moving laterally even if the clip breaks or becomes disengaged. The brace assembly includes a stop that is secured to the brace plate and a tapered wedge that is disposed between the stop and the rail brace. Upon driving the wedge longitudinally of the rail, lateral force is applied to the rail brace and the rail. The stop and the wedge employ a longitudinally extending tongue and groove to prevent relative vertical movement therebetween. The junction between the wedge and the rail brace is defined by mating convex-concave surfaces. A shear member such as a cotter pin prevents the wedge from being retracted once the wedge has been driven to a desired longitudinal position. Because the wedge cannot be moved inadvertently, lateral force will be applied continuously to the rail brace by the wedge.