Getting around New York City in a wheelchair has long been an exercise in frustration, but it could become easier after officials announced a legal settlement Friday mandating that at least half the city’s taxi fleet be wheelchair-accessible by 2020.

The details of how to achieve that goal haven’t yet been worked out and taxi owners immediately questioned who was going to shoulder the cost of upgrading the fleet. But the settlement, which resolves a lawsuit brought in 2011, was cheered by advocacy groups for people with disabilities.