Mexico City's airport struggles to handle overflow of passengers, flights.(The Dallas Morning News)

MEXICO CITY _ Like most institutions in this metropolis of 18 million people, the airport teeters near capacity, just like the jammed roadways and strained electricity grid.

Yet, the Mexico City International Airport has weathered a heavy increase in passengers, volcanic eruptions that deposit slippery ash on runways and poor visibility from the capital's smoggy haze.

Now, a routine maintenance job has knocked it to its knees.

Authorities shut down one of the airport's two runways for repaving on March 19. Since then, air travel in Mexico has turned into a nightmare of canceled flights, irate passengers and delays of up to 12 hours.

The chaos, analysts said, is a wake-up call to government authorities who have yet to decide where to build an alternate airport. Otherwise the near future could look as grim as this past week.

Flight monitors that usually give off cool white letters spelling out "on time" or "arriving" have been replaced by entire screens with yellow "delayed" warnings or the emergency red of "canceled" flights.

"The runway issue is killing us, killing our company," said Kevin Corrigan, 36, as he waited Friday for his wife to arrive from Columbia, S.C. She was two hours late.