Subject to the provisions of this Section, the County Council may, by local law, impose and provide for the collection of development impact fees for financing up to 50% of the capital costs of additional or expanded transportation projects required to accommodate new construction or development. Any impact fees imposed under this Section shall be adopted in accordance with a general statement of public policy adopted by the County Council to impose impact fees in areas of the County in which the level of new construction or development is creating a need for additional or expanded transportation projects. The County Council shall: Adopt a method for determining the timing and location of the areas in which an impact fee is to be imposed; and In lieu of payment of development impact fees imposed under this Section, provide credit for: Payments made for the construction of, or improvements to, permanent or interim public transportation projects authorized for impact fee funding as provided in this Section; and Payments related to subdivision approval as provided in subsection (c) of this section. A local law enacted in accordance with this section may authorize the Planning Board to impose a development impact fee in lieu of mandatory transportation improvements otherwise required to achieve transportation adequacy at the time of subdivision approval if: The proposed development is located within an area of the County in which impact fees are authorized by the County Council under this section; Transportation adequacy is determined by the Planning Board according to the guidelines for the analysis of the traffic impact of development proposals in Prince George's County; The local law provides standards for and the Planning Board finds that it would not be equitable or economically reasonable to require the applicant developer to fund the entire cost of road improvements necessary to achieve an acceptable peak hour service level under the guidelines; The impact fee in lieu of mandatory transportation improvements otherwise required is only imposed with the consent of the owner of the property subject to the subdivision approval; Payment of the impact fee is an express condition of the subdivision's approval and noted on the final plat before recording the plat in the land records; The County Department of Public Works and Transportation has approved the estimated cost of required transportation improvements; The local law provides standards for the Planning Board to determine the impact fee allocable to the proposed subdivision subject to the following: The impact fee payable shall be calculated on the basis of daily vehicle trips for all developments to be served by the transportation facilities involved; Except as provided in item (c) of this item, the impact fee shall represent a reasonable allocation of the total estimated cost of required transportation improvements and shall be calculated based on 150% of the subdivision's pro rata share of the total trips for the traffic facilities involved; and The local law may provide for an adjustment in calculating the subdivision's share of trips by reduction to account for preexisting trips that do not originate or terminate within Prince George's County; and The local law provides standards for the Planning Board to require the applicant or owner to construct interim improvements if the Planning Board finds that the improvements would materially improve the existing traffic conditions in the roadway or intersection. Any impact fees collected by the County: Shall be retained in the escrow account maintained in accordance with Subsection (e) of this Section; May be used at the discretion of the County Department of Public Works and Transportation only for the capital costs of additional or expanded transportation projects within the areas of the County in which the impact fees are authorized by the County Council under this Section; and May not be transferred to any other account. The escrow account required by subsection (d) of this section shall be budgeted, maintained, and accounted for on an aggregate basis as a restricted fund by the County Department of Finance and may be expended only for the purposes set forth in this section in any area of the County in which impact fees are authorized by the County Council under this section.