An experimental model animates contiguous computer cartograms by distorting the topological lengths of their edges. Using traffic information for the city of Lisbon, the authors distort a road map to depict traffic velocities. Areas of the city distend when velocities are low and compress when velocities are high. This model is applied to two visualizations: a trajectory visualization of vehicles, creating a temperature map for traffic velocities, and a figurative visualization that portrays Lisbon as a system of pulsing blood vessels. The proposed model can efficiently generate and animate edge-based cartograms with low representation errors.