** Originally published at World Now:
Maria Guadalupe Garcia usually spends two hours traveling from her home in southeast Mexico City's Tlahuac borough on bus and microbus to reach the city's west side.
On Tuesday, Garcia, 60, was one of the first riders of a new subway line inaugurated by the mayor and Mexico's president. She said she expects that those two hours of commuting will be reduced to 45 minutes.
"It's going to benefit us so much," Garcia said, standing with her husband, Angel Hernandez, on the platform of the Mixcoac station. "Now, we'll go with calm."
The 12th line of this city's moving hive of a subway system -- the loved and loathed el metro -- opened to the public in what leaders called the most significant and complex public-works project in recent Mexican history.
The new Line 12, or Gold Line, cost about $1.8 billion and is a capstone for the administration of outgoing Mexico City Mayor Marcelo Ebrard. The line also represented an unprecedented test for engineers, planners and politicians who had to fend off vigorous protests and legal challenges from some residents.
For riders, the line makes a crucial alteration to the transit landscape of Mexico City: It adds a lateral connection across the southern end of the metro map, crisscrossing four lines and creating transfer points where previously none existed.
The line also connects Tlahuac, a large, semirural expanse on the southeastern end of the metropolis, to the subway grid. End to end, Mixcoac to Tlahuac, the line stops at 20 stations across 15.5 miles of tunnels and elevated tracks.
More than 380,000 people are initially expected to use Line 12 daily. Overall, nearly 4 million passengers ride Mexico City's subway every day, making it one of the largest such systems in the world.
"This is an immense project for Mexico City," Ebrard said. "It is the longest line and turned out to be most complex. We are very proud of our engineers, our workers."
President Felipe Calderon said he was proud the federal government supplied funds for Line 12, meant to commemorate the 2010 bicentennial of Mexico's independence.
"It was worth it," Calderon said. "This ... is a sustainable solution to the problems of mobility and transport in Mexico City. Moreover, it minimizes the impact of pollution on the city, and that's fundamental."
By noon, smiling, cheering riders were joining the inaugural train on which Calderon and Ebrard briefly rode. An hour later, at Mixcoac station, commuters were already moving about the transfer point as hardy residents of this city do: earphones in, bags held close, eyes alert to the journey ahead.
* Photo: Juana Cisneros, 59, and Jose Hernandez, 52, were among the first riders of the new Mexico City subway line, Line 12, on Tuesday.