The White House is opening its back lawn to some 15,000 people for the arrival of Pope Francis next week. It's promising a traffic nightmare for everyone else in the area. 

White House press secretary Josh Earnest offered the crowd estimate for Wednesday's White House arrival ceremony for the pope. He tacked on a traffic forecast, predicting "traffic's going to be a mess." 

If 15,000 people do attend, that will surpass the more than 13,000 who were invited for Pope Benedict XVI's arrival ceremony in 2008. Some 6,000 attended Pope John Paul II's arrival in 1979. 

Earnest took note that the government is encouraging federal workers in Washington to telecommute during the pope's visit. 

While in Washington, the pope also will address Congress and celebrate Mass at the basilica.