Evidential grids have recently been shown to have interesting properties for mobile object perception. Possessing only partial information is a frequent situation when driving in complex urban areas, and by making use of the Dempster-Shafer framework, evidential grids are able to handle partial information efficiently. This article deals with a lidar perception scheme that is enhanced by geo-referenced maps used as an additional source of information in a multigrid fusion framework. The paper looks at the key stages of such a data fusion process and presents an adaptation of the conjunctive combination rule for refining the analysis of conflicting information. This method relies on temporal accumulation to distinguish between stationary and moving objects, and applies contextual discounting for modeling information obsolescence. As a result, the method is able to better characterize the state of the occupied cells by differentiating moving objects, parked cars, urban infrastructure and buildings. Another advantage of this approach is its ability to separate the drivable from the non-drivable free space. Experiments carried out in real traffic conditions with a specially equipped car illustrate the performance of this approach. A 1 2understanding capability of an autonomous vehicle in terms of drivable space characterization and mobile object detection. It is important to identify free space for path planning, but it is also important to distinguish static objects (e.g. road signs) from mobile road users (cars, cyclists, pedestrians) who are often vulnerable. If a mobile object is detected at the roadside, the vehicle can reduce its speed or modify its trajectory to avoid a possible collision. To model the vehicle environment, the approach presented here uses multiple 2D occupancy grids [3]. The information processing is based on the Dempster-Shafer theory of evidence and pignistic decisions. The map is treated as an additional source of information, on a par with the other sensors. We propose a method for incorporating this prior knowledge in an embedded perception system intended for autonomous navigation. Digital maps have been used as prior knowledge for several years already [4]. The use of drivable road maps for localization [5], [6], perception [7], navigation and driving [8] has proved to be of high added value. Geodata was also successfully used for mobile navigation in [9]. Some research works have also contributed to the map updating problem [10]. In a previous paper, we have focused on the use of highly accurate and precise special-purpose maps [11] at first. As opensourced maps such as OpenStreetMap have been successfully employed [12], [13], we propose an updated perception approach that uses this freely available map source.This paper describes a unified approach applicable to a variety of problems based on spatial representation of the environment using Dempster-Shafer theory. This theory was originally applied to occupancy grids [14], and it is only recently that researchers have made use of it in...