1. An apparatus comprising: a database that models roads, the database stored on a computer-readable medium, wherein the database includes data entities that represent roads, data representations of physical road lanes, wherein the data representations of physical road lanes refer to those data entities that represent roads that represent those roads of which the physical road lanes are a part, wherein each data representation of a physical road lane includes data indicating start and end points of the represented physical road lane; and an adjacency attribute indicating what lies adjacent to the represented physical road lane on a right side and a left side thereof; and a driving assistance device for a vehicle, the driving assistance device configured to: receive measurements of an environment of a vehicle from one or more sensors; access the adjacency attribute from the database; and generate, in response to the adjacency attribute, a driving warning to a driver of the vehicle or engage a mechanical system for operation of the vehicle; wherein the adjacency attribute indicates at least one of the following: (i) another lane, which can be entered by a lane change, (ii) another lane but which cannot be entered, (iii) a lane that is in the process of forming, (iv) a lane that is in the process of ending, (v) a shoulder, (vi) another drivable surface that is not a lane or shoulder but vehicle navigable, and (vii) no drivable surface.