Fossil tracks represent a direct window onto the lives of extinct organisms, being formed and preserved in situ. Because track morphology is determined by limb motion, foot anatomy and substrate consistency, studies of fossil tracks can provide insight into producer, behaviour and palaeoenvironment. However, each determining factor is subject to variation, either continuous or discrete, and this variation may be co-dependent, making it difficult to correctly interpret a track. In addition to variance from the track-forming variables, tracks and tracksites are subject to further obfuscation because of time averaging, even before the effects of weathering, erosion and exposure are accounted for. This paper presents a discussion of the factors that may confound interpretation of fossil tracks, trackways and tracksites, and reviews experimental studies that have attempted to elucidate and eliminate these sources of confusion.