OK, so it is feasible. The chainages need to be pre-calculated rather than iterated over time. Then use the Counter add-in by Daniel_Woodcock1 to animate.Please see the link below. It should be also possible to use the Web Request node and then save the iterations to an external file as suggested by Dimitar Venkov.
https://forum.dynamobim.com/t/how-to-generate-an-input-to-vary-over-time/3170/8
For the end result please see the video below:
https://markomarko.tinytake.com/sf/MjM2MzgwMV83MjAwMjU0
The python node is currently very basic - just simple slowing down before the stop and accelerating afterwards…
Now to animate over a real route, add more vehicles, add vehicle interactions… calculate capacity 
the fun part…