If you needed reminding that information technology isn't always the answer to efficiency, you may want to check out New York Times technology reviewer David Pogue's recent pieces on the modernization of the air traffic control system. Last week he wrote about the automatic dependent surveillance - broadcast system (ADS-B), a GPS-based system that gives pilots a view of the air traffic around them. The idea is that with that kind of control (and not having to depend on air traffic controllers so much), planes could fly closer together and relieve some of the congestion that has led to record delays this past year.

But wait.

The ADS-B is part of a bigger modernization effort at the Federal Aviation Administration called NextGen. This week, Pogue again wrote about the modernization efforts because he got quite a bit of feedback. In this week's article, he highlighted some comments to the first article. Here's one:

David: I read your article on ADSB with great interest, as I have been an air-traffic controller for nearly 30 years. But please: before you encourage the spending of $20 billion, ask the FAA to let you go to the Newark or La Guardia towers any weekday from 3-6 p.m. You will quickly discover that providing more space in the air is not what is needed: it's concrete.

New York, Chicago, LA… they all need concrete. A runway can only have one airplane on it at a time. The backup is at the runways.

Another reader quoted a comment by Republican John Mica of Florida, who said at a recent hearing that the NextGen system would improve airspace capacity only about 6 to 8 percent.

What's needed is the old kind of infrastructure: concrete.