Under a task order for this on-call project, KOA prepared a construction-period traffic study and conceptual engineering diagrams for intersection closures.  The roadways of Evans Road and Lake Perris Drive would be closed immediately to the north of Ramona Expressway to construct replacement bridge structures as part of the proposed project.  This traffic study assumed that Perris Road would be the primary detour route, with east-west connections to the north along Krameria Avenue and Iris Avenue.  The traffic study area included five intersections on this route and two intersections adjacent to the bridge closures on Ramona Expressway.  Six roadway segments were evaluated as well, for traffic increases due to the detour routes.  The engineering analysis focused on partial closures of the Evans Road/ Ramona Expressway and Lake Perris Drive/ Ramona Expressway intersections, and optimized the configuration to allow for the least reduction in approach lanes and/or turn pocket lengths.  Coordination meetings included DWR staff and local City agencies.