Lane estimation apparatus and map generation apparatus

A lane estimation apparatus, comprising:

• an external circumstance detection part detecting an external circumstance around a subject vehicle;
• and
• an electronic control unit including a microprocessor and a memory connected to the microprocessor, wherein
• the microprocessor is configured to function as
• a lane estimation unit that estimates a current lane in which the subject vehicle travels, based on the external circumstance detected by the external circumstance detection part, and
• the lane estimation unit estimates a time-based current lane every a predetermined time when the subject vehicle travels in a predetermined section, calculates a parameter indicating a frequency of the time-based current lane after traveling of the subject vehicle in the predetermined section, and estimates the current lane in which the subject vehicle has traveled in the predetermined section, based on the parameter.

A lane estimation method, comprising:

• detecting an external circumstance around a subject vehicle;
• and
• estimating a current lane in which the subject vehicle travels, based on the external circumstance detected, wherein
• the estimating includes estimating a time-based current lane every a predetermined time when the subject vehicle travels in a predetermined section, calculating a parameter indicating a frequency of the time-based current lane after traveling of the subject vehicle in the predetermined section, and estimating the current lane in which the subject vehicle has traveled in the predetermined section, based on the parameter.