Drivers could experience delays through sections of Interstate 70 during the next year as construction crews replace an emergency access structure that runs beneath the interstate near Eisenhower-Johnson Memorial Tunnel, the Colorado Department of Transportation announced Thursday. The replacement of the emergency access structure is necessary to protect the structural integrity of the road which emergency vehicles, including law enforcement and ambulances, use to navigate busy portions of the interstate between the Eisenhower-Johnson Memorial Tunnel and Silverthorne, the department said. The structure is a single-lane concrete box culvert built during the tunnel's original construction in the 1960s. Over the course of many decades the structure has deteriorated and requires "immediate replacement," the agency said.