The project will close an 8-mile gap in HOV lanes between Riverside and San Bernardino counties. I-215 currently has three lanes in each direction on this section of freeway. The HOV lane addition will occur by re-constructing the outside and inside freeway shoulders and restriping the lanes to allow for three general purpose lanes and one new carpool lane in each direction.
Two railroad bridges will be rebuilt and bridges crossing the Union Pacific railroad tracks, I-10, and the Santa Ana River will be widened. Improvements to interchanges at Barton Road in Grand Terrace and Washington/Mt. Vernon in Colton are planned.