Industry Leading Durability With an outdoor life of at least 10 years, our sign posts certainly are the most durable in the market. U-channel sign posts look brand new even after years of exposure to sun, wind, and weather abuse. Baked-enamel coating extends the life of posts and makes them rust-proof. USA’s Oldest Traffic Sign Post Manufacturer Family owned since 1918, we take immense pride in our sign posts. Being one of the oldest certainly means we know this business in and out. Our South Dakota factory is the oldest manufacturer of metal signs and sign posts in the USA. Economical sign posts are ideal for property signs or for temporary signs. Compliant Our 6 feet tall and 2-1/4' wide sign post is compliant with NCHRP (National Cooperative Highway Research Program) 350 and approved for nationwide use