Kansas City police take aim at "high drivers" on 4/20

(CBS) - Kansas City police want you to know that they know all about 420, and they plan to crack down on anyone driving under the influence of marijuana on this April 20/420 - a date lots of pot devotees consider a "high holiday."

Kansas City police Sgt. Daniel Graves told local station KMBC that April 20 is a day of widespread marijuana use because of the slang "420," said to originate with California high school students in the early '70s who would meet smoke pot at 4:20 pm when detention let out.

Graves also wants to bring awareness to parents who may not know that 420 is code for pot, reports the station.

"It's in all kinds of rap, hip hop and rock songs your kids may be listening to," said Graves to KMBC. "We're finding that many parents don't realize this code."

Armed with this knowledge, police say they're on the lookout for traffic violators who offer a hint of marijuana. They planned to set up checkpoints and to target areas near schools and parks, Graves told the station.

Slow drivers and drivers who turn abruptly into fast-food parking lots should beware - police may mistake you for driving under the influence on this "weed Wednesday."