Economic and social impact aside, the Taipei-Ilan Expressway is a spiritual successor to the Central and Southern Cross-Island Highways; all illustrating man's determination to overcome natural obstacles. However, if the environment along the expressway is not subject to strict protection, this new project may well end up in the same position as the Central Cross-Island Highway--collapsing after heavy rains, and ruined beyond repair.
除了社經衝擊外，北宜高速公路是繼中橫、南橫之後，台灣另一項「人定勝天」的艱鉅工程，但若不能以最高標準做好沿線的生態保護，可能會逐漸淪入如目前中橫般「逢雨必坍，修無可修」的困境。