Honolulu police are setting up checkpoints to crack down on impaired drivers over the summer.

The checkpoints are to be set up at unannounced times and locations starting this weekend through the end of August. 

Police say July and August are popular months for family reunions and high school graduation parties. 

As of June 29, 25 people have been killed in 23 traffic collisions on Oahu.

Speed, alcohol and drugs were factors in 12 of those crashes. 

The public is reminded that promoting liquor to those under 21 is a misdemeanor punishable by up to a year in prison.