LAST week, the Port Authority of New York and New Jersey put off, yet again, deciding between two proposals for a nearly $4 billion project to rehabilitate the dilapidated Central Terminal Building at La Guardia Airport. Disdain about the disrepair, crowds and grubbiness at La Guardia is so pervasive that Vice President Joseph R. Biden Jr. has likened La Guardia to an experience “in a third world country.”

But piling billions of taxpayer dollars into upgrading La Guardia, which opened in 1939, won’t solve its fundamental problems. It can’t easily expand. Its two runways and four terminals are surrounded on three sides by water, making landing difficult and hazardous. Parking is a nightmare.

Moreover, some 50,000 people who live near La Guardia are subjected to a level of noise higher than the standard deemed acceptable by the Federal Aviation Administration, according to a 2011 study by the Regional Plan Association. (Another 95,000 living near Kennedy International Airport, also in Queens, and 44,000 living near Newark Liberty International Airport, are affected as well.)

The popularity of La Guardia, which serves nearly 30 million passengers a year, is almost entirely related to proximity — a typical nine-mile trip to Midtown Manhattan can be done in about 20 minutes during off-peak hours, 10 to 30 minutes less than it would take to get to Kennedy or Newark. But proximity comes with a price.