Prodded by rules and financial incentives, a growing number of airports are banning diesel shuttles and urging taxi companies to buy more alternative-fuel vehicles.
Mineta San Jose says it has fully converted all of its 34 shuttles to run on compressed natural gas and has eliminated the use of more than 1.3 million gallons of diesel fuel since 2003.
Boston also encourages cleaner driving for passengers by providing preferred parking to those who drive to the airport in hybrid cars. It also doles out front-of-the-line privileges up to two times a day for taxis with cleaner fuel, a program modeled after one at San Francisco International.
"There are too many rental-car or hotel shuttles at airports with just two or three passengers in them," Howards says. "They're traveling billboards."
Green practices are also seeping into the airfield. Boston Logan will be the first U.S. airport to reduce toxic emissions by using runway asphalt heated at a lower temperature — 250 to 275 degrees, up to 75 degrees lower than is required for traditional "hot mix" asphalt.
Logan's Sleiman says warm mix uses 20% less energy to make, produces 20% fewer greenhouse emissions when applied and lets the airport use a higher percentage of recycled asphalt pavement in the final product. If the asphalt performs as expected, the airport will use it for future paving projects, he says.
Meanwhile, gate electrification is becoming an industry standard practice. Each gate is equipped with a 400-hertz electrical connection that allows parked aircraft to shut off the engine, thus saving jet fuel, and still run lighting and other avionics. Another practice of saving jet fuel at gates that is growing in popularity is to pump in preconditioned air from the terminal to the aircraft. Large tubes extend from the terminal to the aircraft belly, delivering air conditioning to passengers so that the aircraft's air conditioning systems can be turned off.
Boston Logan has the first LEED-certified terminal in the USA, a recognition awarded by the U.S. Green Building Council for constructions that follow its criteria of energy-saving measures. About 20% of the materials used to build Terminal A in 2001 were locally manufactured. It also features sensors that turn off lights at unoccupied gates, large and airy glass walls that reduce the need for lighting and heating, low-flush toilets and a roof that was painted in white to better reflect the sunlight.
Atlanta's Hartsfield-Jackson is also in the midst of a restroom upgrade aimed at conserving water. It's installing new toilets that use 1.28 gallons of water per flush vs. 1.6 gallons used by the current units. It also recently completed refitting men's urinals to use just half a gallon per flush, compared with one gallon in previous models.
Airport authorities estimate the changes will save 44 million gallons of water a year, a reduction of 13% in airport water usage. They had considered waterless urinals, but found that they might not be popular with travelers. They smelled.