And your friend or someother people can check this data free of cost and can decide at what time they can leave from home. Remember if you are helping someone today by turning your location On, tomorrow someone else may help you when you are at home.
Google doesn't want to interrupt your privacy, so it will delete start and end points data of the location immediately. If there are more users at a place who uses maps to send data, then Google combines the anonymous data and hence maintaining your privacy. So next time when you start your journey, just enable Google maps with my location thus making world a better place to live.