This guide is based on the current knowledge and practices for the design@ construction@ and maintenance of concrete parking lots placed on the ground. It emphasizes the aspects of concrete pavement technology that are different from procedures used to design and construct slab-on-grade such as streets@ highways@ and floors. This guide is not a standard nor a specification@ and it is not intended to be included by reference in construction contract documents; ACI 330.1 can be used for these purposes.Parking lots have most loads imposed on interior slabs surrounded by other pavement@ providing some edge support on all sides. Highway and street pavements carry heavy loads along and across free edges and are subjected to greater deflections and stresses. Streets and pavements are usually designed to drain towards an edge where the water can be carried away from the pavement. Parking lots are usually designed so some of the water is collected internally and is conveyed away through underground systems. In urban areas where rainfall runoff from large impervious surfaces is regulated@ parking lots often serve as detention basins (not addressed in this guide). This means that the pavement should store water for a period of time without incurring any damage due to loss of support from a saturated subgrade. Parking lots often accommodate appurtenances@ such as lighting standards@ drainage structures@ traffic islands@ and landscaped planting areas. Provisions for these appurtenances should be considered in the design of the jointing system and the layout for construction.