A clash with the Barbarians in Hong Kong opens the tour on June 1 before the 37-man squad heads Down Under for the remaining nine fixtures that will climax in a three-Test series against the Wallabies.
Roberts, one of four centres selected by head coach Warren Gatland, said: "In a foreign country like Australia it can be quite intimidating. It will be a daunting atmosphere. The sporting prowess of Australia means that whenever it comes to the big occasion they always raise their game."
He continued: "Whether it's union, league, cricket or athletics, they pride themselves enormously on sport. They will raise their game against the Lions and the whole country will go berserk. That's when it becomes intimidating.
"There's 37 players, plus staff, against a nation. It's back-to-the-walls stuff from minute one, like it is on every Lions tour. It's the ultimate challenge in rugby."
Roberts was voted player of the series in South Africa four years ago on a tour that was notable for the unity within the squad. The 2009 Lions were deemed a success, even if the Springboks did prevail 2-1.
That experience has taught Roberts the value of players from the four unions buying into the Lions ethos immediately, stressing the role socialising can have in bringing rivals from the RBS 6 Nations together.
"A Lions tour is very unique. There are lots of players you've played against in your career but never with," said Roberts, who trains in Under Armour clothing. "The aim of the tour is to get to know those guys, bond and be singing from the same hymn sheet on the pitch as quickly as possible.
"A team-bonding session over a few beers is pretty important in my eyes. In rugby you always like to share a beer with the other guys.
"Picking good people is also important, guys who will contribute and get on well with each other. I went in 2009 and it's the best tour I've ever been on. Hopefully this series will top that."