sentences:  As a result of the confluence of these three routes at State Route 91 in Santa Ana Canyon, there is often a bottleneck of eastbound traffic during evening rush hour that begins there and continues across the county line and into Corona.Worsening the bottleneck further is the southern terminus of State Route 71 just beyond that.However, there are numerous projects in the planning stages that are aimed at alleviating traffic through the canyon and into Corona and Riverside.