When somebody is pulled over for suspicion of driving under the influence, police are going to do everything they can to make a final determination as to whether or not the person is legally drunk. This typically leads to the use of a breathalyzer test.
El Paso and Teller counties have special DUI Courts. They are designed for people who have had multiple DUIs and are considered high need or high risk. Some of the people who are accepted in the DUI Court program have had multiple drug and/or traffic offenses.
When people think of driving under the influence, they often first think of alcohol use. However, as the laws have changed in Colorado so that marijuana is legal, this is something that has also come to indicate getting behind the wheel after getting high.