1. A method comprising, at a mobile device: identifying two or more subsets of grid points corresponding to an electronic map representing a particular environment, wherein said two or more subsets of grid points comprise a first subset including a first plurality of grid points representative of a first transitional region including one or more hallways or one or more corridors, or a combination thereof, within said particular environment for use in position estimation by said mobile device while in a first transitional motion state and a second subset including a second plurality of grid points representative of a second transitional region for use in position estimation by said mobile device while in a second transitional motion state; selecting said first subset of grid points representative of said first transitional region for use in position estimation by the mobile device based, at least in part, on a determination that said mobile device is in said first transitional motion state based at least in part on at least one signal from at least one motion sensor; and determining an estimated position of said mobile device within said particular environment based at least in part on said selected first subset of grid points.