PATH PLANNING DEVICE, PATH PLANNING METHOD, COMPUTER PROGRAM PRODUCT

A path planning device configured to plan a traveling path on a future route of a vehicle includes a lane evaluation unit, a score accumulation unit, and a lane selection unit. The lane evaluation unit is configured to estimate a risk score of each chronological section of each traveling lane parallel traveling lanes, the risk score representing a traveling risk. The score accumulation unit is configured to accumulate the risk scores for each traveling lane. The lane selection unit is configured to select the traveling lane for the traveling path based on evaluation accumulated values. The lane evaluation unit is configured to estimate a base score based on static information. The static information contains a traveling difficulty for the vehicle at a change node. The lane evaluation unit is configured to estimate the base score such that the traveling risk is higher as the traveling difficulty is higher.