The Arizona Department of Transportation has made the largest sale of excess property in its history. ADOT sold a piece of land along the I-10 in Phoenix for $28.7 million.

The 21-acre parcel is located along the north side of the I-10 near Sky Harbor International Airport. ADOT advertised the land earlier this year and eight bidders took part in an auction of the property.

ADOT spokesman Doug Nintzel said money from the sale will be used for a future project.

“We are designing a project to add new lanes along I-10 in areas between the I-17 split interchange near Sky Harbor airport, around the Broadway curve, down to the Loop 202 Santan Freeway," Nintzel said. "So that’ll be a major endeavor.”

Nintzel said construction for that project is scheduled to start in 2021.

Nintzel said part of the land will be used for the widening project, but the rest of the property isn’t necessary to complete the work.

"Our engineers are far enough along in that process for the widening project where they have determined how much of the property is needed,” he said.