With the highest growth among modern transportation types over the last several decades, air travel has evolved into the "norm" for long-distance travel. Not only is aviation a much faster way to travel, but also --- statistically speaking --- it is the safest. Aviation has also made travel more convenient and less physically demanding, enabling travel for everyone, from the elderly and kids to the disabled.
The downside is that travel by air is still costlier compared to travel on land or sea. Travelers must also factor in the time spent waiting in airports, the hassle of security lines and baggage checking and claiming, all of which add to travel time. Air travel can also be a victim of the weather, as bad weather can cause delays in flights. Land vehicles, although by no means immune to bad weather, can still travel in harsh conditions, even if at a slower pace and be quicker if the destination is in a relatively close range.
Like people, goods moved through the air usually reach their destinations quicker and safer. This has opened doors in business, leading to goods being delivered at a much quicker pace. Aviation's transporting services range vastly, from common mail that needs to arrive faster to emergency helicopters transporting patients out of hospitals.
Air cargo, however, is more expensive per mile compared to maritime shipping. If time isn't a factor, then maritime shipping tends to still be the preference of most businesses due to higher profit margins.
The main benefit of airports is interconnection. Airports keep no one apart. They connect nearly every area of the world. If one airport doesn't fly to a certain location, it can be almost guaranteed that they likely fly to a location that then connects to the original destination.
The only downside to airports is their large size. Runways and terminals must be built large --- and oftentimes large in number --- to house the vast number of airplanes. This sometimes places airports far outside of cities.
Aircraft, maintenance equipment and refueling facilities all emit volatile organic compounds, carbon dioxide and nitrogen oxide, which are harmful to the environment. A 1996 study by the Natural Resources Defense Council showed increasing aircraft emissions of these pollutants against deceasing emissions by vehicle-related industries. Although not a problem for most people, for those living near an airport, noise pollution can be a continuous aggravation as well.
