Laboratory test results from six different concrete-filled steel-grid bridge deck panels of one and two spans with approximate midspan loadings were compared with finite difference solutions of a governing differential orthotropic plate equation. The orthotropic plate equation was based on assumptions related to fully composite behavior. The effects of changes in properties due to increasing loads were examined. A means of predicting deflections in other laboratory panels was developed, and the results were extended to permit the estimating of deflections in actual bridge decks.