 When the portion of DE 1 between Dover and Smyrna opened , road signs , with the exception of speed limit signs , were in metric units in anticipation of the United States converting to the metric system . The section of DE 1 between Dover and Smyrna had exit numbers based on <unk> while the section between Tybouts Corner and Christiana originally had exit numbers based on mileposts . In 1997 , the exit numbers along the portion of the route between Tybouts Corner and Christiana were changed to reflect <unk> . 
