20 ILCS 25/20

The H+T Affordability Index or substantially equivalent affordability measure, where available, shall be adopted by DCEO, IDOT and IHDA as (1) a tool for the development of plans in Metropolitan Planning Organization areas and (2) a consideration for the allocation of funding for public transportation, economic development, and housing projects in Metropolitan Planning Organization areas; the distribution of economic incentives to businesses in Metropolitan Planning Organization areas; and the siting of public facilities in Metropolitan Planning Organization areas, where appropriate.