The timing of the Modernisation Plan was also unfortunate, as just months after its publication the train driver's trade union, ASLEF, called a strike that lasted for 17 days, causing major disruption to the network. Many of BR's long-standing freight customers – especially smaller business and industrial users which provided much of the remaining wagonload and less than carload freight traffic – were forced by necessity to start using road transport and never returned to the railways, which hastened the decline in railway freight traffic and rapidly undermined the logic and business case for the Plan's renewal and expansion of large marshalling yards.