Having nobody behind the wheel is better than a drunk driver.

That's essentially the message from autonomous car service Waymo, which will offer half-off rides to the public around the holidays in a partnership with Mothers Against Drunk Driving, the organizations said on Thursday.

The announcement came as the organizations launched the 35th "Tie One On for Safety" campaign, where drivers are encouraged to place red ribbons on their vehicles as a reminder to drive sober.

“As we enter the busy holiday season between Thanksgiving and New Year’s Day, we want everyone to stay safe and enjoy this festive time by making sure plans for a designated driver are a top priority,” MADD National President Alex Otte said in a press release. “Whether you’re going out or hosting friends and family at home, planning for a non-drinking driver or confirming your guests have one is the most important decision you can make.”

Waymo, run by Google's parent company, is offering 50% off one ride from noon Nov. 24 and noon Jan. 2, to any rider who uses their smartphone app and is traveling in the company's East Valley service area.

To redeem the discount, riders can use the promotional code "MADD21" when they hail their ride.

Waymo brought autonomous vehicles to Chandler in 2016 and has incrementally expanded both the area where the cars operate and who is allowed to ride in them.

Since 2017, some of the cars have had nobody behind the wheel, but until late last year, that was only for certain tests and select riders. Then the company opened its sometimes driverless ride service to anyone.

“Everyone deserves to have fun and get home safe during the holidays,” Mauricio Peña, Waymo’s chief safety officer, said in a press release.

Waymo runs 300-400 vehicles in Arizona.

The Waymo One ride service is available in a "geofenced" area that is about 50 square miles covering parts of Chandler, Mesa and Tempe using Chrysler Pacifica minivans.

Waymo now operates Jaguar I-PACE vehicles in Arizona but they are not yet part of the service. It also is common to see Waymo vehicles driving in areas beyond the area that is available for rides.

Waymo and MADD point to National Highway Traffic Safety Administration data indicating fatal car crashes spike during the holidays, particularly on the night before Thanksgiving, Christmas and New Year's Day.

“We know the past year-and-a-half has been like no other, and we hope everyone will do their part to stop this public safety crisis,” Otte said. “It will take everyone to stop these tragedies, and we are so grateful to Waymo for their partnership and for sharing our vision of zero deaths and zero injuries caused by drunk and drug-impaired driving.”

Reach reporter Ryan Randazzo at ryan.randazzo@arizonarepublic.com or 602-444-4331. Follow him on Twitter @UtilityReporter.

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This article originally appeared on Arizona Republic: Waymo to discount holiday rides in autonomous cars in metro Phoenix