The Taipei-Ilan Expressway passes through rugged mountains and valleys with spectacular scenery. To keep the impact on the environment caused by the construction work to a minimum, much use was made of bridges and tunnels.
北宜高速公路行經深山、溪谷，大多地形陡峭，風景優美，為了減少開挖帶來的震動，避免破壞自然環境，全線的橋樑及隧道特別多。