Officials recommend that U.S. citizens apply for their passport as early as possible to prevent delays. Beginning June 1, 2009 everyone is required to have a passport or federally approved ID when traveling by land or sea. A passport is already required for international air travel, but under new legislation, travelers will no longer be able to only furnish a driver's license and birth certificate when crossing U.S. land and sea borders. Instead, a U.S. passport or other federally approved ID will be required. As such, a record number of citizens are expected to apply for a U.S. passport close to the June 1 deadline, potentially resulting in delays in processing time. In fact, passport applications are projected to increase from 16 million to 18 million as the deadline approaches. Officials recommend applying for a passport now, as October thru December is usually when the state department receives the fewest passport applications. The State department notes that more staff has been added to alleviate long delays in processing time; however, it is still strongly recommended to apply for a passport as soon as possible. U.S. Passports are valid for 10 years, and cost $100 for an adult passport and $85 for children under 16. The passport regulations are part of the Western Hemisphere Travel Initiative. The first part of this U.S. law took effect in 2007 and required passports for all air travel, including those travelers re-entering the U.S. from Bermuda, Canada, Mexico, and the Caribbean.