The planned TxDOT project will start at FM 359 in Waller County, passing through Fort Bend County and end at Mason Road in Harris County. (Courtesy Pexels) A $550 million proposed project to widen about 13 miles of the Katy Freeway, also known as I-10, is one step closer. The planned project will start at FM 359 in Waller County, passing through Fort Bend County and end at Mason Road in Harris County.