Road line recognition device and driving assistance device

A road line recognition device is provided with: a camera (2) that detects the situation in the vicinity of a host vehicle; a position specifying unit (111) that specifies, on the basis of the detection result of the camera, the position of a road line for specifying the lane on which the host vehicle travels; a prediction unit (112) that uses a Kalman filter to predict the position of the road line at the current point in time on the basis of the position of the road line in the time series determined prior to the current point in time; a reliability calculation unit (113) that calculates the reliability of the determined position of the road line; and a recognition unit (114) that recognizes the position of the road line on the basis of the calculated reliability. A reliability calculation unit (113) calculates the reliability on the basis of the Kalman gain of the Kalman filter and the difference between a predicted value, which is the position of the road line at the current time predicted by the predicti