NOGALES — After nearly 10 years of planning and construction, Arizona’s largest port of entry is ready to challenge Texas and California as the nation’s busiest commercial crossing.

The official opening ceremony Wednesday of the Mariposa Port of Entry marked the conclusion of the nearly $250 million expansion project. Construction began in 2009 and the port stayed open throughout.

Improvements at the international crossing include eight commercial lanes, a pedestrian processing area, a dedicated bus lane and 12 passenger vehicle lanes.

Local and federal officials — including Sen. Jeff Flake, Rep. Raúl Grijalva and U.S. Ambassador to Mexico E. Anthony Wayne — spoke during the ceremony, highlighting the importance of trade with Mexico to the economy.

“Our best trading partner is Mexico; this port of entry is going to be a vital linchpin in increasing economic growth, increased flow of visitors, goods and services, commerce, and yes, enhanced security,” said Grijalva.

Mayor Jonathan Rothschild said Tucson would be an immediate beneficiary of the port’s expansion.

“For Tucson this day is a significant milestone in our economic development as a city,” he said. “As we go out and we market our city as a logistics hub, as a manufacturing hub, as a place where you want a headquarters to do business internationally, we had to have this piece in place.”

Originally built in 1973, the port was designed to process 500 trucks a day, said Bruce Bracker, chairman of the Greater Nogales Santa Cruz County Port Authority.

When the Port Authority was formed in 2005 to actively lobby state and federal officials, volume was exceeding 1,800 trucks during the peak of the season and long wait times had taken their toll, pushing business to other ports.

The new crossing can process 4,000 trucks a day, said Nogales Mayor Arturo Garino, and represents a real challenge to Texas and California.

“Our neighboring states, they’re going to have to worry now. We’re not going to worry about anybody else — they’re going to worry about Nogales,” he said .

The ports of entry in Laredo and San Diego occupy the two top spots for loaded truck traffic. In 2013, 1.3 million trucks passed through the Texas port, while 556,262 crossed through California.

Over the years, Nogales has held steady with approximately 250,000 truck crossings. More than 50 percent of the fresh produce entering the United States from Mexico crosses through Mariposa.

Local officials hope the new port expansion and the support gathered from state and federal agencies means there is a renewed recognition of the vital role trade with Mexico plays in Arizona’s economy.

“There were state lawmakers that would be more than happy to close the border and never have anything to do with Mexico,” Bracker said. “But a lot of people have really come around to recognize that trade with Mexico is important and relationships with Mexico are important, and you can tell by the fact Arizona opened up a trade office in Mexico City.”

Ironically, if anything puts the brakes on the promise of increased commercial crossings through the port, it will be Mexico’s slow development of the infrastructure on the Sonoran side, where traffic jams are common.

But officials said they are optimistic and have seen a real effort on the part of the Mexican government, including the recent commitment to invest approximately $1 billion in highway improvements — including federal Highway 15 from Nogales to Mexico City.

Ramón Guzmán Muñoz, mayor of Nogales, Sonora, said the opening of the Mariposa port was a push in the right direction.

“I would see the inauguration of this important commercial building as a challenge to improve as far as our part is concerned and respond to be on equal footing,” he said. “Pretty soon we’ll be inviting you all to our grand opening.”

Contact reporter Luis F. Carrasco at lcarrasco@tucson.com or 807-8029. On Twitter: @lfcarrasco