 The city government independently funded $47 million in interim corridor improvements, including the addition of auxiliary lanes, sidewalks, and bicycle lanes.A 2016 study of the corridor's safety by WSDOT concluded that the outdated design of the roadway had reached its capacity and was in need of immediate improvement to handle expected traffic volumes.An earlier WSDOT study recommended $300 million in projects to widen SR 169 to four or six lanes between Black Diamond and Renton.