The operation and performance of road networks are affected by limitations of infrastructure and fluctuations in demand, factors which are known or can be predicted. Short-term disruptions, such as traffic incidents and crashes, are unpredictable in nature and also have significant ramifications on the performance of the road network. This paper presents an empirical analysis of traffic volume and incident data, obtained from the Roads and Maritime Services, to compare incident and non-incident traffic conditions across 5 pairs of competing parallel routes in Sydney, Australia. Disruptions resulted in greater volatility of traffic volumes and adaptive routing was evident through noticeable shifts in route occupancy between the competing routes. These insights support the need for adaptive equilibrium based modelling tools accounting for the acquisition of information by a user in light of a disruption.