1. A vehicle dimension prediction method comprising: compiling a database of known vehicle dimensions for a plurality of vehicle models, the known vehicle dimensions including a known width and a known length, the database including a vehicle identification field, a width field, and a length field, the database being derived from publicly available data; producing a set of simulated observed dimensions based on the database of known vehicle dimensions, the set of simulated observed dimensions including a set of images of a plurality of the vehicles models at a plurality of different orientations and known actual dimensions associated with those images; training a machine learning model by applying the simulated observed dimensions to input nodes and the known vehicle dimensions to output nodes of the machine learning model during training; acquiring sensor data associated with a first vehicle observed by a sensor system of an autonomous vehicle; determining a plurality of observed dimensions of the first vehicle based on the acquired sensor data; determining, with a processor, a plurality of predicted actual dimensions of the first vehicle by applying the plurality of observed dimensions to the machine learning model, the plurality of predicted actual dimension including the known length and known width of a vehicle model whose known vehicle dimensions have been compiled in the database, wherein the autonomous vehicle is configured to use the predicted actual dimensions to plan a path that avoids intersecting the first vehicle.