It’s the U2 30th anniversary Joshua Tree Tour. As reported on the Arizona Department of Transportation (ADOT) blog, "One of the one of the best-selling musical acts in history with more than 20 Grammys, played Glendale on Tuesday night. Because of U2's international recognition, ADOT played off of the band's lyrics to promote highway safety and even managed to catch the attention of the band!”
ADOT announced in advance that they would display a couple of U2-related safety messages, stating, "With U2 performing at University of Phoenix Stadium on Tuesday, Sept. 19, we’ll display a couple U2-related safety messages on a selection of overhead signs throughout the state with the goal of reminding drivers to avoid dangerous driving behavior.
"We’ve posted music-related safety messages on overhead signs in recent weeks when Metallica, Neil Diamond and Ed Sheeran performed in Phoenix and referenced the popular song “Despacito.” We want to grab people’s attention with these messages and prompt conversations about safe driving.”
The whole effort is to encourage safe driving practices. As explained in ADOT's blog post, "We hope the messages you see on the highway change driver behavior by prompting conversations in homes, the workplace and elsewhere. The keys to safety are in your hands, even where the streets have no name."
The traffic safety messages caught the attention of U2, which posted the following on Instagram, where it received nearly 62K likes: