A routine traffic stop on Interstate 55 leads to a drug arrest.  On Tuesday just before 4 PM the Missouri State Highway Patrol stopped a 1999 Dodge truck for a traffic violation.  While approaching the vehicle the trooper became suspicious.  Consent was granted for a search and a K-9 unit indicated the presence of drugs.  Officers found a hidden compartment in the toolbox leading to the discovery of 50 pounds of marijuana.  35-year old Jose Herrera of Houston, Texas and 35-year old Carlos Reyes-Benitez have been arrested for felony drug trafficking.