Construction of Metrolink’s 24-mile-long Perris Valley extension is 70 percent complete. Work on the $248 million project began a year ago. Soundwalls in the Riverside area have been finished. Most of the remaining work centers on installing track paralleling an existing BNSF line. John Standiford, Deputy Director of the Riverside County Transportation Commission, predicted that the Metrolink extension will be completed between this October and December.