The word vacation typically conjures images of fun-filled getaways, whether it’s sipping cold drinks on a hot beach; tearing down the slopes of a picturesque mountain; or taking in the cosmopolitan sights of a big city.It does not bring to mind the many obligatory trips – weddings, family events and reunions – that sometimes make up a significant portion of many travellers’ holiday budgets.According to an April 2013 American Travel Behavior Survey by discount travel site Hotwire.com, some 21% of US adults spent $197 billion last year on trips they felt obliged to make – so-called “oblication travel”. What’s more, the first survey in 2012 found that 41% of Americans use the majority of their vacation budgets on these duty-led trips.For an industry that typically views travel as either business- or pleasure-related, the news comes as a surprise. It also provides insight into the myriad reasons people travel and how they spend their money.“With so much money allocated to obligatory travel, travellers may be thinking about putting off the fun trips they want to take because they believe they won't be able to afford them,” Hotwire.com wrote in its report.However, travelling for obligatory events like weddings and reunions shows commitment to relationships and to rituals that reassure and comfort us, according to sociologist Jeffrey Alexander, who told CNN that travelling for family and friends “is a way of showing… that you value your close friendships”.And savvy travellers can have their cake and eat it too – that is, salvage time and money for leisure travel – with a few common-sense tips.Pick and choose the obligation trips you attend, turning down invitations or get-togethers that strain budgets – or emotions. (In other words, if you can send a card in lieu of visiting your politically contentious uncle across the country for his 50th birthday, by all means, do it.)Look for opportunities to combine obligation and leisure travel. For example, a trip to Hawaii for a destination wedding is a perfect excuse to take a few extra days on the beach. Even cities provide good opportunities. For example, a family reunion in Chicago is an ideal set-up for a getaway to Lake Geneva, Wisconsin (about 75 miles away), while a business meeting in New York is an excellent opportunity to enjoy the scenic Hudson Valley region (which starts as little as 20 miles away).Combining obligation and pleasure trips also carries with it implicit savings – think of it as one flight and set of accommodations for two trips. Save some cash by boarding with family or friends at night while pleasure-tripping during the day.Still, if a vacation just isn’t a vacation unless it’s away from family and obligation, Hotwire suggests a list of bargain destinations for US travellers who’ve spent most of their money doing just that. Topping its list are Washington DC, Chicago, Vancouver, the Dominican Republic and Turkey.