Traffic restrictions due to wind on the Fehmarn Belt bridge

This report documents the calculations carried out in order to estimate the wind climate at the site where the Fehmarn Belt bridge is planned. Further, an estimate of how often and for how long traffic restrictions will be enforced according to statedcriteria (sec. 3.2) is given. This estimate is given both as a total percentage of time and as a mean distribution of restrictions over the year.

We perform the same analysis for the Øresund and the Great Belt bridge and compare the result with the actualfractions. Only during the last year of operation of the Øresund bridge the criteria are the same as used in this report and here the comparison is satisfactory. We estimate that the prospective Fehmarn Belt bridge will be closed roughly 2% of the timefor light roadway vehicles (unloaded trucks and caravans), corresponding to 7 days per year.

This is slightly less than for the Fehmarnsund Bridge. For the Great Belt bridge the corresponding actual fraction is 1.5%, despite the fact that this bridge usesstricter criteria. The most important difference between the bridges in this connection is their orientation with respect to the prevailing wind direction.

If all the large bridges (Øresund, Great Belt and Fehmarn Belt) used the same criteria the FehmarnBelt bridge would be closed approximately twice as much as the two others. The majority of these restrictions are likely to take place in the winter time and can be significantly reduced with wind screens.