Answer:
if the marginal gain on implementing the speed limit is equal to or greater than $500 per day.
Explanation:
Governments and businesses always balance the cost-to-benefit ratio when undertaking a project.
The point at which the benefit is equal to the cost is called break-even point.
When the benefit is above the break-even point the entity is making profit.
For speed limit implementation to be sustainable and not cause losses, Montana should ensure benefits are above $500 per day.