Would building more runways solve the problem?

Let's consider some facts first. Seventy percent of all US air traffic is handled by about 30 US airports (the 30 busiest US airports). The 30 busiest airports over the last 10 years have expanded their total number of new runways by only 6. At the rate of air traffic growth, the US would need to add about 25 more runways to keep up with the demand. Right now 15 new runways are being built with completion anywhere from 3 to 7 years away.

Building more runways at many of the major airports would only minimally help. First, it would take quite a few years to get additional runways built. While the construction is going on, the amount of air traffic will continue to increase. That means, that by the time all the runways would be constructed the operational capacity for those runways will have already been surpassed. In other words, if enough runways were built in a short period of time, this would solve the problem.