The Doobie Brothers have been rockin’ down the highway for 42 years and it still remains fresh for founding member and longtime principal Tom Johnston, who has been with the group for most of that time.

The classic rockers bring their long string of hits — “Takin’ It to the Streets,” “Listen to the Music,” “China Grove,” “Black Water,” “What a Fool Believes” — as well as tunes from their 2010 album, “World Gone Crazy,” to the Comcast Center next Thursday on a double bill with fellow ’70s FM staples Chicago. Expect to find both groups crowding the stage at the end of the night for a celebratory encore. Singer-songwriter-guitarist Johnston checked in from a Raleigh, N.C., tour stop to share “five things he’s grateful for” in the Doobies’ long career. (Shockingly, the band’s appearance on a very special episode of “What’s Happening!!” did not make the cut. )

1. “Having been working this long and still having the ability to get up there and move people, and make them part of the show we put on.”

2. “Having written songs that people equate with tough, happy, or transitional times in their lives.”

3. “Being in a band that is respected by its peers in the business as well as fans for its musicality/musicianship.”

4. “Still creating new and relevant material that can still be considered ‘valid’ in today’s very different musical climate.”

5. “Being proud of what we’ve been able to accomplish, both as a band, and individually under the name ‘The Doobie Brothers.’ Very grateful.”

The Doobie Brothers play the Comcast Center with Chicago Aug. 16 at 7:30 p.m. Tickets are $28.50-$93.50 at 800-745-3000 or www.livenation.com.