The name of the event tells you what the organizers of the event hope you will do Saturday.  Jennifer Villegas of Wives Behind the Badge was a guest on KFYO to spread the word:

“Say ‘Thank you’ to an officer.’  If you happen to see one specifically on the 15th, please make an effort to say ‘Thank you.’”

"I would  also like to ask you to grab a blue ribbon from a local craft store and tie one around your car, like a visual thank you.   My vision is that I can see a field of blue across Lubbock’s streets on the 15th .