If you must force drivers to use an alternate route, than make it explicitly clear with a heavy-duty aluminum "Alternate" sign.
Standard: If used, the ALTERNATE or ALT auxiliary sign shall be mounted directly above a route sign.
Have you purchased this item?
Top
Size: 12" x 24" Material Type: Engineer Grade Reflective Aluminum Sign, 80 mil Verified PurchaseGood sign.
Just as expected. Good quality and fast shipping!