Relatively few experiments have been reported so far which have been specifically addressed towards the detection and handling of intersections by CV. An intersection or junction is usually specified as either a gap in the lateral lane or road marking or as a stop line across the approach lane. Since most driving manouvers so far have been performed on highway-like roads, the most frequent manouver upon encountering an intersection or junction area consisted in driving straight across. In these cases, a gap in the lateral lane markings is simply considered as a failure to pick them up correctly: it is handled by straight extrapolation of previously estimated lane parameters.
If, however, a sharp turning manouver had to be performed at an intersection or junction, a road model of the specific intersection/junction has been used. Complications arise if the visible section of lane boundary markings become difficult to detect or if lane boundaries temporarily disappear from the field of view of a camera oriented straight ahead, i. e. along the tangent of the current vehicle trajectory. In such cases, the camera has to be mounted on a panning head or more than one single camera has to be used. Very few systematic experiments have been reported so far regarding such conditions.
Additional complications may arise if the intersection or junction area becomes complicated enough to no longer facilitate capturing the section essential for lateral control entirely by a monocular video stream. Apart from relating a virtual vehicle trajectory to two or more images at the same time, the initialization and tracking of lane boundary markings in the different image planes may become difficult due to combinatorial problems during the association step between edge elements and model segments.