Apple's labs are full of projects that never see the light of day, or that are shelved for years until the time is right. For example, the tablet that became the iPad emerged first, but it was put aside so that the iPhone could be launched first. But according to 'people familiar with the matter' who the Wall Street Journal spoke with, the team that has been working on an electric car (possibly self-driving) under the codename 'Titan' has made enough progress for the company to give the project "committed" status, with a target shipping date of 2019 (which isn't exactly the same thing as a commercialization date in Apple jargon, so the actually launch could be later).
Of course, all that is always subject to change. The Apple Car could be delayed, or the project could be shelved for some time for whatever reason (something more promising to work on?). The WSJ sources also say that the first version of the Apple Car would't be autonomous (or maybe just partly autonomous?), but that this is a capability that is planned for the future.
Of course, by 2019, maybe Apple will have bought Tesla... You never know, but there are some reasons to think that this could happen: 9 reasons why I think Apple might buy Tesla.