Spare a thought for the world’s taxi and bus drivers. Japanese mobile Internet companyDeNA Co.will join the race to make human drivers obsolete. DeNA said it will launch a joint venture with Tokyo-based ZMP Inc., known for developing autonomous vehicle technology, with an eye toward building a driverless transportation business. DeNA said it will provide two-thirds of the capital for the new company, tentatively named Robot Taxi, and ZMP would come up with the rest. The two companies said in a statement Tuesday that the venture will combine DeNA’s “Internet services know-how with ZMP’s automated driving technology” to realize robot taxis and buses.