I'd like to be able to create buffers/zones/rings of transit times using Denver's public transportation system. For an example of what I'm talking about, check out triptropnyc.com - I don't need it to look nearly as nice, and I only have one origin point of interest.
My thought so far was to distribute random points around the area of interest and then pass those points to the Google Maps API a bit at a time. Once I had the travel times, I could then interpolate between the points to get the buffers - going back from more points if necessary to smooth out the estimates.
Would that be a valid approach? Are there other ways of estimating transit times that I should consider? Perhaps other sources of data that would be more useful or easier to get?
Let me know what you think.