Constant speed instead of constant time would seem interesting. With the
scenario type and
data-duration derived from path length this is within reach. Morphing the abstract map to its real geographic coordinates would be pleasing to see, as something akin to the artwork "Tokyo Arteria".
Check out this Tempelhof "geo-choreography", observing real humans drawing lines at their own speed.
Also, Nate Parrott did subway travel time visualisation of New York here.