Environmentally Optimised Design (EOD) is a philosophy focused on creating the most efficient design-set for a given road, which can range from upgrading the whole road to doing spot improvements.
EOD can be thought of through the following two simple ideas:
The idea is to make the provision of year-round access as economical as possible.
Often, the majority of a road can be accessible, but just one short section of impassable road renders the route in-accessible to many. This section should be given a robust pavement solution, leaving the remainder which is not causing a problem. In this way money is spent only where it is necessary.
This is a shift away from two common approaches: