When the board of chosen freeholders shall deem it proper and necessary to acquire lands or rights in lands for the extension or enlargement of any developed park or recreation ground or site for such proposed park or recreation ground, which has been acquired as herein provided, or for the laying out of any boulevard or roadway leading to any public park or recreation ground from an established public highway, and the board of chosen freeholders cannot agree with the owner or owners of such lands, or rights or interest therein, as to the price or terms of purchase thereof, or when, by the legal incapacity or absence of the owner or owners, or for any other reason, no agreement as to the purchase thereof can be made, the compensation shall be determined and paid agreeably to the provisions of chapter 1 of the title Eminent Domain (s. 20:1-1 et seq.).

In any such proceedings the commissioners appointed shall ascertain, fix and determine the amount of special benefits for the laying out or maintaining of any boulevard or roadway or the improvement thereof, as will confer upon any owner property benefits. In all such cases where damages are assessed under the provisions of this article, in favor of the owner of any land or interest therein and benefits are likewise assessed against such owner, the board of chosen freeholders, when both the award of damages and the assessment of benefits shall have been confirmed, may deduct the amount of the benefits assessed from the damages awarded and set off such benefits against any such damages by proper charges and credits in order that the excess of damages, if any, shall be paid, and the excess of benefits, if any, be collected.