In _The Expanse_ series, characters experience sustained Gs during space travel, not just during acceleration, which doesn't make sense. For instance, here's several passages from _Leviathan Wakes_, the first book in the series (tried to omit anything that could be a spoiler):

> Walking through the *Rocinante* felt surreal. [...] To walk through the spare, functional corridors, thrust gravity holding him gently to the floor...  
> [p 359]

And:

> Alex had the *Rocinante* running at three-quarters of a g for 2 hours while the crew prepared and ate dinner. He would run it back up to three when the break  was over [...] Once the gravity had dropped from the crush of high acceleration, the whole crew quietly gathered in the galley...  
> [p 366]

Both passages suggest that there are more Gs during acceleration, but always some amount of g-force just from moving. However real-life physics dictate that you feel g-force only  when you accelerate. If you're driving on the highway at a constant speed of 80mph, you aren't being pushed back into your seat. How is the _Rocinante_ generating constant g-force, unless it is constantly accelerating? After hours and hours of travel under any amount of g-force from thrust, wouldn't the speed become unsafe? Or is there something I missed?