The Department also expects the cost of dealing with the backlog in road maintenance to have increased since its last estimate in 2019 of between £7.6 billion and £11.7 billion. The Department told us that all the evidence suggested that the backlog would have become worse, given the severe weather conditions and very wet winters in the years since its estimate, as well as accounting for inflation.19 The Asphalt Industry Alliance estimated the cost of the backlog in 2023–24 as over £15.6 billion, based on a survey of local authorities.20