Passenger traffic at Denver International Airport was down by 6.4 percent in March compared with a year ago, writes the Denver Business Journal, which notes that more than 4.3 million passengers visited the airport in March compared to nearly 4.6 million in the same month in 2008. Traffic at the airport was down 5.7 percent for the first quarter compared with 2008. The down-turned economy contributed to the decline, but so did the threat of bad weather on March 26 and 27, which caused airlines to cancel hundreds of flights, according to The Denver Post. On the bright side, the decline probably means less hassle with crowds at the airport. Another factor contributing to less hassle is the 1-year-old “Clear card” program that allows passengers to streamline security checks with a $199 membership. The program is working well, reports 9News, which adds that it may be upgraded.