GREENWOOD VILLAGE, Colo. — In just a few days, thousands of tourists will flock to Colorado to celebrate one of the largest cannabis festivals in the country.  But the pot party won’t just be in Denver.  The City of Greenwood Village is expecting a big crowd on 4-20 as well.

Rap star Snoop Dog will headline a concert at Fiddler’s Green Amphitheatre that day.  And because it’s a marijuana celebration, police want to make sure people are aware of what they can and can’t do.

“We’ve been working on this traffic and flow plan for several months and we’ve got a good plan,”  John Jackson, Greenwood Village Police Chief, told FOX 31 Denver.

He knows the event will bring a unique set of challenges to the city.  The department is planning to add extra officers on 4-20.  But the chief stresses, his goal is not to scare away people.  He wants to educate and inform all guests.

“We’re going to be handing out cards that speak to what you can and can’t do,” Jackson said.

On the “can’t do” list: smoking marijuana in public view.  That’s the law across Colorado and the Fiddler’s Green website says the venue won’t tolerate it either.

It’s not just about pot though.  With 18,000 people heading to the concert, resident know they’ll be dealing with a lot of traffic.  Police promise they have a plan to help with that too.  They’ll also encourage people to carpool or take RTD.

NoDUIColorado.org (a website developed by state agencies to cut down on impaired driving and substance abuse behaviors) has another option, as well.  They’ve partnered with Uber and Yellow Cab to give discounts to area residents starting Friday, April 17.  Promotional codes will be available through both the Uber app and Yellow Cab’s Z-trip app.