yes, consider a base speed of 10k
10 10% levels will bet you to 20k
20 10% levels will get you to 30k
the big catch is that 20k does NOT have half the travel time of 10k
I once spent about an hour starting to figure our what the speed algorithm was, after that hour i gave up, but I can promise you that double speed will not get you to half travel time, likewise double the 'distance' is less than double the travel time. the equation goes something like:
(wow i'm finishing off some of those rough calculations now...)
(5000/sqrt(speed))*sqrt(distance)
...
5000*sqrt(distance/speed)
this underestimates apparently
I thought it might be the real equation since it was so close to something nice, but the real one will be of a similar form. (constant is based on STANDARD, i dont' know if speed or travel time is changed in other universes)