D&D 5E (2014) Chase scene: Ending turn on jump

[Satyrn]

But, you can walk across a bridge as slow as you like, and it won't drop you in the drink.

 

[TheCosmicKid]

For what it's worth, there's precedent. 3E, at least, explicitly stated that you can end your movement in mid-air.

 

[jaelis]

First, I agree that you can't jump further than your movement ... in a single turn. Whether Crawford is saying that or not isn't 100% clear. Or maybe I'm biased.

You have every right to interpret it as you see best.
For completeness I guess I should include the other convos on the topic, though I know you feel the same about them:

Q: What happens when Jump gives a jump distance greater than walking speed?
Crawford: Your jump is limited by how far you can move; each foot jumped uses a foot of movement (PH, 182).
Q: So casting Jump on a character with a 20 STR and a move of 30’ is effectively pointless?
Crawford: 20 Strength running long jump: up to 20 ft. With jump spell: up to 60 ft. with a speed of 30 ft. and Dash.

Q: A dwarf 18 STR, walk 25ft, under a jump spell, max long jump 74 ft. BUT: with dash can only go 50ft. How to get max benefit?
Crawford: The jump spell lets you leap farther than normal. Use a spell like longstrider or haste for greater speed.

Q: Monsters like Barlgura has a trait allows 40ft jump while having base move of 30. Does it need to dash to get the full benefit?
Mearls: I'd say no, but Crawford disagrees

 

[Oofta]

You have every right to interpret it as you see best.
For completeness I guess I should include the other convos on the topic, though I know you feel the same about them:

Huh. As far as

Q: Monsters like Barlgura has a trait allows 40ft jump while having base move of 30. Does it need to dash to get the full benefit?
Mearls: I'd say no, but Crawford disagrees

I've always assumed it was a special movement type, like flying.

 

[Hriston]

I think it makes sense to limit the distance you can clear on a single jump to your total movement for the turn on which you begin your jump, provided you have enough movement on your next turn to complete that distance. After all, considering that the vertical component of a long jump is negligible, no one is going to spend much more than a second in the air regardless of the jump's total length, so using more than one full round of movement on a single jump would have the result of stretching movement that should only take about a second over a period of time longer than six seconds. Jeremy Crawford's ruling makes sense in this respect but is also somewhat irrelevant to the OP. A 10-foot leap doesn't exceed the total movement for the turn on which the PCs are jumping, especially considering that they already appear to be taking Dash. So the way I'd resolve their action is that they run 55 feet to the edge of the gap and begin the 10-foot jump, completing only 5 feet of the jump by the end of the round. On the next round, they complete the jump and, assuming they take Dash again, have another 55 feet of movement left to use. I see no problem caused by splitting the jump this way, whereas not allowing the jump based on not having enough movement left to complete it forces the PCs to waste some of their movement without providing a clear benefit to the game.

 

[Saeviomagy]

Being forced to cut a jump short because of your movement is a symptom of 5e having movement speeds that are roughly half real world, while having jump distances that are about 2/3rds real world. Really running movement should be about 120ft/round up to 240 and jump distances should be from about 10-30ft, without magic. That gives you at best 1.5s hang time.