The unofficial start to summer has travelers crisscrossing the country, with more than 42 million Americans taking to the roads, skies and rails this weekend, according to AAA. Experts warn roads could be jam-packed Monday as vacationers head home. Emilie Ikeda has more. » Subscribe to NBC News: http://nbcnews.to/SubscribeToNBC » Watch more NBC video: http://bit.ly/MoreNBCNews NBC News Digital is a collection of innovative and powerful news brands that deliver compelling, diverse and engaging news stories. NBC News Digital features NBCNews.com, MSNBC.com, TODAY.com, Nightly News, Meet the Press, Dateline, and the existing apps and digital extensions of these respective properties. We deliver the best in breaking news, live video coverage, original […]