The first new international rail bridge between the United States and Mexico in more than 100 years is finally operational.

Built in a rural area west of Brownsville, the bridge over the Rio Grande and the connecting tracks took 15 years to complete, and the price tag ran over $120 million. On Friday morning, freight trains carrying goods from the Mexican state of Tamaulipas into Cameron County rumbled along the West Rail Bridge at long last, marking an important step toward reducing congestion at the border as trade with Mexico booms, local officials and business experts said.

“Providing this new link to move goods and services more efficiently is going to bring enormous advantages and opportunities to the consumer, the supplier and to markets throughout North America,” Cameron County Judge Pete Sepulveda Jr. said.

The West Rail Bridge replaces an old rail connection that cut through a busy section of Brownsville and Matamoros, Mexico, including school zones, and interrupted trade during peak business hours.

Currently, three northbound trains and three southbound trains cross the bridge every day, but business experts say that by shifting rail traffic out of congested areas, the new line can speed the flow of goods moving between the two countries and boost economic growth in the region.

“If you think about trade volumes right now with Mexico, they’re only going to grow, and rail is a critical component of cross-border logistics,” said Garrick Taylor, director of policy development with the Border Trade Alliance, a nonprofit group of economists and private-sector interests that advocate for international trade.

The rail line runs from the Port of Brownsville to Monterrey, Mexico. With the expected speed and efficiency of the bridge, experts say the advantageous transportation infrastructure will attract prospective business interests, especially in oil and gas.

“The expansion of the oil industry in Mexico will eventually move more oil through that particular crossing,” said Juan Villa, program manager for the Mexico City office of the Texas A&M Transportation Institute. “Moving oil across the border is problematic, and although some pipelines are being built, a lot of fuel will need to move by rail.”

In the first six months of 2015, trade with Mexico topped $262 billion, according to Census data. In Cameron County, motor vehicle parts, commercial vehicles, fuels and cellphone equipment topped the list of imports and exports.

The bridge project faced delays on several occasions because of logistics problems on both sides of the border. By the end, about $45 million in federal, state and county funds were spent on the 6-mile rail line in South Texas, with Mexico investing an additional $75 million for a 7-mile stretch in Tamaulipas. Border security measures include X-ray scanning machines that examine rail cars for illicit cash, drugs and other contraband.

“To have this new transportation artery is paramount to the success of the region,” said David E. Allex, chairman of the Cameron County Regional Mobility Authority, which oversaw the project in Texas. “I know that we will be able to attract more investment because of this project.”

anelsen@express-news.net

Twitter: @amnelsen