 The Öresund Bridge was designed by the Danish engineering firm COWI.The justification for the additional expenditure and complexity related to digging a tunnel for part of the way, rather than raising that section of the bridge, was to avoid interfering with air traffic from the nearby Copenhagen Airport, to provide a clear channel for ships in good weather or bad, and to prevent ice floes from blocking the strait.The Öresund Bridge crosses the border between Denmark and Sweden.