On June 1, 2020, Transport Action Network (TAN) filed a suit in the High Court of Justice challenging the legality of the UK government's Second Roads Investment Strategy, covering the years 2020-2025, on climate and air pollution grounds. TAN, an environmental advocacy NGO, named the Secretary of State for Transport as the defendant and Highways England Company, appointed by the Secretary to implement the strategy, as an interested party. TAN listed four grounds for its suit: 1) the Secretary failed to take into account the impact of the roads strategy on achieving climate objectives, in violation of the Infrastructure Act of 2015 and the objectives of the Paris Agreement; 2) the Secretary unlawfully failed to establish a metric for measuring GHG emissions; 3) the Secretary unlawfully failed to ensure levels of air pollutants do not exceed limits set in air quality regulations; and 4) the Secretary unlawfully failed to carry out a Strategic Environmental Assessment of the roads strategy.
On July 21, 2020, the High Court admitted the case on the first ground - that the Secretary unlawfully failed to take into account climate impacts. On October 19, 2020, TAN renewed its application for the court to admit the air pollution claims, and a hearing was held on the issue on October 29, 2020.