Thirty-one percent of employees say that they won't use all of their vacation days this year, according to a survey by Expedia, an online travel agency.

The survey found that employed U.S. adults will leave an average of three vacation days on the table. Respondents reported an average of 14 paid vacation days this year.

Eighteen percent of respondents said that they've cancelled or postponed vacation plans because of work, and 29 percent admitted they have trouble coping with stress from work at some point in the vacation cycle.

Twenty-four percent of respondents said that they check work e-mail or voicemail while vacationing, up from 16 percent in 2005.

Expedia analyzed the vacation habits of employed workers in the U.S , Canada, Great Britain, Germany, France, Spain, Italy, and for the first time, the Netherlands and Austria. Canadians receive an average of 17 annual days, two less than 2007 but still three more than Americans.

Among the European countries studied in the past, all workers receive more vacation days in 2008 than 2007. Great Britain has a two day increase over 2007, with 26 days, and Germany , Spain and France all saw increases of one day, receiving 27 days, 31 days and 37 days respectively. Employed workers in the Netherlands and Austria are awarded an average of 28 days in 2008.