Cyclists must perform continuous threat assessment when choosing the safest path through the road environment. However, different situational interpretations exist among cyclists and other road users (e.g. car drivers) regarding risk perception and the responsibilities and liabilities of each party towards mutual awareness. Automated in-car, hazard-detection technology has potential to mitigate the risk to cyclists by warning drivers or taking control of their vehicle if a collision is imminent. However, the success of such technology is predicated on its ability to make an appropriate assessment of the behaviour of cyclists and accurately predict their future trajectory, in all situations. Six focus groups involving 24 cyclists and 13 car drivers were conducted in the UK and Netherlands, with different stakeholders assembled separately. The focus groups aimed to uncover the cues that indicate a cyclist’s future path and the characteristics of the environment that may affect their choice, from both perspectives. Twenty-seven cues and twenty-five characteristics were identified and categorised into 4 themes: cyclists’ appearance, communications and signalling, movement and position of bicycle, and environment and conditions. Results indicated consistency between groups, but were tempered by a cultural perspective, reflecting the higher social status afforded to cyclists in the Netherlands. The findings can be used to develop classification and coding schemes for naturalistic observations and to inform the development and evaluation of in-car cyclist detection and avoidance technology.