Eliciting tacitly wielded knowledge from expert practitioners can be very difficult. Task analysis methods have harnessed a variety of naturalistic techniques to enrich the knowledge elicited, but few have incorporated the generative methods used in participative design. Research was conducted in the Australian rail industry using a novel macro-to-micro participative approach that sought to involve the same participants in all stages of inquiry, and yielded a rich dataset that emphasised the impact of expertise and operation type on internal route representation. The method itself facilitated exceptional auto-ethnographic rapport and was received well by industry.