Most major U.S. markets experienced higher hotel room night volumes and average daily rates during the second quarter

, according to TravelClick. The luxury hotel segment grew most quickly with a 10 percent increase in room nights from a year earlier. Overall, travel agent bookings through global distribution channels generated a year-over-year revenue increase of more than 13 percent. "Travel agency room nights through the GDS will continue the growth trend, surpassing 100 million room nights by the end of 2006," according to a TravelClick statement. "The GDS will continue its position as one of the highest ADR channels, tracking 30-plus percent higher than its Internet counterparts."