Overall, over one-third of Americans (38 percent) are more likely to take a vacation this summer compared to last summer. Millennials' optimism about taking vacations, however, is not fully shared by Americans aged 35 and up: More than half of Millennials (56 percent) plan to travel more this summer compared to summer 2017, in contrast to 35% of Gen X respondents (ages 35-54 years old) and 22 percent of Baby Boomers (ages 55+).

Millennials are as bullish about taking vacations in the year ahead as they are on their 2018 summer vacations. They plan to vacation more in the next 12 months compared to the 12 months prior, with 55 percent of Millennials planning to increase their vacation plans, in contrast to the more cautious future vacation planning of Gen X (31 percent) and Baby Boomers (20 percent). And 34% of Millennials plant to spend more than $5000 on upcoming vacations, the most of any other age group.

Other key findings in the survey include:

• Vacation spending and gender: While the biggest group (42 percent) of all survey respondents plan to spend between $1,001 to $5,000 more while on vacation in the next 12 months compared to the past 12 months, males are significantly more likely to splurge than females, with 37 percent of males planning to spend more than $5,000 in the next 12 months, compared to only 15 percent of female respondents.

• More education + more income = more likely to take vacations this year: Americans with postgraduate degrees (64 percent) and with household incomes above $200,000 (71 percent) are the most likely demographic segment to take a vacation this summer than last summer. And the same individuals also are most likely to spend more than $5000 on vacations in the next 12 months compared to the previous 12 months (44 percent and 68 percent respectively).

• Millennials on the road: Nearly half (49 percent) of respondents have traveled for business/leisure within the last year, with Millennials having traveled the most in the last 12 months (51 percent) compared to Gen X and Baby Boomers (each at 48 percent).

• Baby Boomers least likely to double down on travel: Baby Boomers are least likely to increase their plans to travel in the next year compared to last year, likely an indication this demographic has established a consistent approach to planning and going on vacation. More than 78 percent said they would travel either the same amount or less in the next 12 months.

• Direct or aggregate bookings dominate: The most common method for booking air travel is directly through an airline's website (30 percent) followed by a fare aggregator website (21 percent), such as Priceline or Expedia. Surprisingly, for hotel bookings, Millennials are the most likely to use traditional offline travel agencies (23 percent), compared to Gen X and Baby Boomers (7 percent and 6 percent respectively).

• Convenient and customized technology are key for younger travelers: Millennials, who have grown up using digital technologies, are more likely to use a travel agency to book travel if a mobile app with customized notifications are available. While 44 percent of Millennials are willing to make the switch, only 23 percent of Gen X respondents and an even smaller proportion (5 percent) of Baby Boomers agree.

Erika Moore, Travelport's vice president and general manager for the United States, said, "Travelport's survey is good news for the U.S. travel industry, as Americans are cautiously optimistic about taking vacations this summer and next year. The key is offering consumers, regardless of their budgets, the best air, hotel and other vacation deals, which requires travel providers and travel sellers to deliver a personalized, seamless and stress-free experience at each step of the vacation journey."