The main objective of this research is to correlate the deformation and internal force of the approach slab with the approach embankment settlements and the approach slab parameters such as length and thickness. Finite element analysis was carried out in the present study. This correlation will be used to evaluate the effectiveness of approach slabs and develop guidelines for their structural design. This information will also help determine when settlement controls are necessary. While flat approach slabs may be used for some short span applications, longer span lengths would require very thick slabs. In such cases, ribbed approach slabs (similar to slab-on-beam bridge decks) are proposed in the present study because they provide advantages over the flat slabs. Based on finite element analysis, internal forces and deformations of ribbed slabs were predicted and their designs were conducted. In addition, special studies on a few issues that were not included in the original scope of work were conducted. These special studies including investigating (1) the skew angle effects and the applicability of the developed methodology for right approach slabs to skewed approach slabs; (2) the failure mode/mechanism of the approach slab end and the abutment connection; (3) the applicability of the developed methodology to AASHTO LRFD highway loads; and (4) rating of the developed approach slabs in terms of special trucks.