A three-mode, switched-fractal source has been proposed as an accurate model of low bit-rate (less than 5 Mbps) packet video traffic. The performance of the model is compared with both a simple probability source and a Markov source. The switched-fractal source is found to be a superior model, and is able to accurately reproduce traffic characteristics of two test images up to a 90% channel use level ( rho =0.9). The accuracy of this model, combined with its relative simplicity, makes it an ideal source model for highly-compressed, variable bit rate packet video.<<ETX>>