Overview: While the NEC relies on several large movable bridges which must be replaced or repaired, it also relies on hundreds of smaller, stationary bridges. These shorter bridges carry the NEC over the smaller rivers, roadways, and other natural or man-made features that cross below the Corridor. Many such bridges are over a century old and in need of significant rehabilitation or replacement. The vertical clearance below many of these bridges is insufficient. They are occasionally struck by moving vehicles which can disrupt service. Along the NEC, Amtrak and the Northeast states recognize a need to repair or replace numerous spans to improve reliability and, in certain cases, expand capacity for future service. While the rehabilitation of most such bridges is ready for preliminary engineering, the rehabilitation or replacement of a subset of bridges is ready for construction.