accessibility standards for Federal outdoor developed areas 77 Example A picnic facility has 10 picnic units. None of the picnic units provide mobility features. Ten picnic units are being added to the facility, for a total of 20 units. In order for the facility to comply with the minimum requirement of 20 percent of picnic units providing mobility features, a minimum of two new units, not four, must be constructed to include mobility features. When any of the existing picnic units are altered in the future, at least two of the existing units must include mobility features. The requirements only apply to the picnic units that are altered or added until the required minimum number of picnic units with mobility features is provided at the picnic facility. When an entity is implementing a transition plan for program accessibility developed pursuant to regulations issued under section 504 of the Rehabili- tation Act, which designates specific picnic units to provide mobility features, the entity is not required to provide accessible elements when altering indi- vidual elements within picnic units that are not designated to provide mobility features. When all the elements within a picnic unit are altered, the altered picnic unit must provide mobility features until the required minimum number of picnic units with mobility features is provided at the picnic facility. Dispersion [F245 2 4] Picnic units with mobility features must provide choices of picnic units com- parable to, and integrated with, those available to others.