Security measures intended to prevent the placement of  roadside bombs on a major highway in Afghanistan were  improperly installed, the  Special Inspector General for Afghanistan Reconstruction said in a safety alert last week. The “culvert denial systems” were designed to prevent insurgents from placing improvised explosive devices (IEDs) in roadway culverts, according to the alert, which was sent to the commanders of the U.S. Central Command and U.S. Forces-Afghanistan. “Through our preliminary investigative work, we estimate that a large number of culvert denial systems might have been falsely reported by Afghan contractors as complete when, in fact, the denial systems…