The line from Finsbury Park to Edgware continued to be used for goods traffic, primarily coal, milk and building materials, even into the period when diesel engines had replaced steam locomotion. However, the introduction of the Clean Air Act 1956 established a shift away from coal as a fuel for domestic heating and the demand for coal slumped. At the same time, the expansion of road haulage reduced the demand for rail transportation of other bulk loads and the line closed completely between Edgware and Mill Hill East in 1964 with equipment and track removed by the following year.