Delta Works needed level of flood protection and the resulting costs are a recurring subject of debate, and involve a complicated decision-making process. In 1995 it was agreed in the Delta Plan Large Rivers and Room for the River projects that about 500 kilometres of insufficient dyke revetments were reinforced and replaced along the Oosterschelde and Westerschelde between 1995 and 2015. After 2015, under the High Water Protection Program, additional upgrades are made. In September 2008, the Delta Commission presided by politician Cees Veerman advised in a report that the Netherlands would need a massive new building program to strengthen the country's
Motorways of the Sea land. The routes selected to be Motorways of the Sea should be able to maintain a series of quality criteria; these pertain to frequency, port to port costs, simplicity of administrative tasks. Future routes should compensate for congestion experienced, for example when crossing the Channel (as the similar road networks should do for routes crossing the Alps or the Pyrenees). One envisaged impact of the Motorways of the Sea is energy savings, pollution reductions and more capacity on current overland European transport networks. The adoption of Article 12a of the TEN-T by Council and European Parliament gave a legal framework