Beginning in 1961, a stub of what is now the Inner Loop portion of I‑10 was built northward from the Maricopa Freeway (then I‑10) along 20th Street, ending north at Buckeye Road. This stub was originally designated I-510. The Inner Loop name was given to it in 1969, at which time the highway changed numbers, to I-410. The I-10/I-510 interchange was the first multi-level interchange in Arizona and lasted until the Inner Loop was built as a real freeway in the 1980s. This putative freeway was two lanes in each direction and would have been hopelessly inadequate as a leg of the Inner Loop as it was intended.