Where is David coming from, and where is he going?

Maybe I'm overinterpreting, and initially the TV version of the film did not include the scenes with David's phone call to his wife and the beginning where he pulls out of the garage - they were shot later for the theatrical release. So maybe these questions don't matter much, and the story is about a man driving on a highway for reasons that are of no concern to us. But maybe there's more to it. So I'm wondering: Where is David coming from, and where is he going? The phone call makes it quite clear that he is away from his wife, and she expects him to come home not too late (though he has to meet a client first, otherwise he'll risk losing that account). That would imply he is on his way home. But the very first shot shows him pulling out of a garage that's clearly part of a family house. So we would rather assume he's leaving home in the beginning of the film. Do you think there's something behind this apparent contradiction?