You might actually be familiar with it - used that design for magma elevators in both Moonhome and Deathgame. However, do mind turning into a wall - T-shaped track is necessary (and alternating empty holes on the sides for Ts are necessary), if you don't have over 0,5 tiles/step speed. If you already engraved the tracks, you can just add additional engraving designation. The movement direction is bidirectional, provided it gets past the first ramp; it will go 1z-level/step both ways, with nearly unchanging speed (ground friction only) at any speed past...oh, 0,05 tiles/step (plus whatever it takes to overcome the first ascending ramp - being placed on an impulse ramp is enough to cover both.)
What you have in your opening posts on higher z-levels are actually non-accelerating "invalid" ramps that act as flat track (most useful when messing with water or magma) - and you're going too fast to ascend, hitting a wall instead. A dwarf push moves a cart on something like 1219 tiles straight, iirc (but you tend to hit walls on the way down, so it's not as useful or fast as checkpointing).
Oh yeah, if you try to use corner/ramp turns to go up or down z-levels, mind the sideways drift and ensure another corner to reset it within 10 steps, lest the cart crash into a wall, stop and reverse direction to down/sideways. Alternatively, use non-ramp corner followed by a "rocker" for ascending with a kick.
(Since corners change 'exit' direction on every turn, you could theoretically build nearly as fast 2x2 corner spiral, were it to not drain lot of speed both ways due displacing 5k of it sideways; starting from a rocker you'd have to have an impulse ramp something like every 6-7z where it'd come to a stop, which would make it take around twice as long per z on average and would require some additional hoops to descend.)