SAN DIEGO — Three people were arrested at a driving under the influence (DUI) checkpoint in Lemon Grove Friday night, authorities said.

The San Diego County Sheriff’s Department said deputies from the Lemon Grove Sheriff’s Substation conducted the checkpoint at 7879 Broadway from 8:30 p.m. until 2:30 a.m. Saturday.

During that time, three drivers were arrested on suspicion of operating a vehicle while under the influence of drugs or alcohol at or near the checkpoint, authorities confirmed.

The identities of those arrested were not released.

According to the sheriff’s department, 503 vehicles traveled through the overnight checkpoint and 66 of them were referred for a secondary screening by deputies.

On top of the arrests, 20 citations were issued: 17 for unlicensed drivers and three for drivers with a suspended license, SDSO confirmed.

Authorities say a total of four vehicles were impounded.

SDSO says the primary purpose of DUI checkpoints is to promote public safety by taking suspected impaired drivers off the road.

According to the National Highway Traffic Safety Administration, these checkpoints have provided the most effective documented results of any of the DUI enforcement strategies.