constrain

verb3

1. •
   To keep within close bounds; to confine.

   • But it's not just Castlefield Corridor capacity that constrains services. All the junctions on the lines feeding into the corridor are flat, so they create conflict points as trains pass. — 2020
2. •
   To reduce a result in response to limited resources.
3. •
   To force physically, by strong persuasion or pressuring; to compel; to oblige.