idea: #osmand plugin that graphs predicted on-grade coast/accel/brake trajectories against upcoming advisory & mandatory speed restrictions, in the style of a train speed indicator display
i'll even offer a bounty of, oh, i donno, whatever i'm paying for a tank of petrol at the relevant time
my 999 cc tiny car gets 5.2-4.8 L/100km, on par with new hybrids, but i suspect with some tool feedback i could reliably be even more efficient
@astrid now I want to hack my car's firmware to play the ETCS overspeed warning tone when I exceed the recognized speed limit