WINONA, Minn. – To avoid delays on Highway 61 at the Mankato Avenue roundabout construction, some  motorist are switching to narrow and pocked Lake Boulevard on the bluff side of 61 – and speeding. Police announced plans to step up speed enforcement. Lake Boulevard is posted at 30 mph because of driveways, many of them blind. Also, Lake Boulevard is a regular route for runners, joggers and bicyclists.