Dunn & Newton’s article “Optimal Routes in GIS and Emergency Planning Applications” (1992) heavily discusses the mathematics behind the Djikstra algorithm & its spin-off, the “out-of-kilter” algorithm, and the “out-of-kilter” algorithm’s use in early ‘90s GISoftware and on early ‘90s computers.
The “out of kilter algorithm” that diverts in multiple paths for an increased flow from one node to another, like an increase in traffic in emergency evacuation. I would have liked some more information from this article on the possible uses of network analysis for everyday people, but I agree this could have been difficult as personal GISystem use did not really exist then like it does today. The network analysis that Dunn & Newton discuss uses set points with available road networks for its running example, but they could have considered a world using network analysis that could rely on (unscrambled, post-2000s) GPS & constant refreshing. They briefly mention that some emergency vehicles have on-board navigation systems, which infers that they had the capability to discuss GPS & network analysis further, but did the inaccuracy of GPS at the time affect the emergency vehicles? Also, without these systems, a user would have to start from a set route and end at a set route and be limited to analyzing within a specific area that 1) their computer could hold and 2) their data was collected on, and on-the-fly adjustments (commonplace now) could not occur without extensive coordination.
I am looking forward to learning more about current uses & future advancements, especially now that GISoftware isn’t just reserved for highly specialized people as it was in 1992, and that computers are faster (and that cloud computing, (more) accurate GPS, and mobile devices exist)!