Question: how many cars travel on the bay bridge
[{'answer': 'about 260,000 vehicles a day', 'provenance': [{'wikipedia_id': '165926', 'title': 'San Francisco–Oakland Bay Bridge', 'start_paragraph_id': 1, 'start_character': 260, 'end_paragraph_id': 1, 'end_character': 288, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '165926', 'title': 'San Francisco–Oakland Bay Bridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 359, 'bleu_score': 0.7665996562102521, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10480261237326905474}, 'section': 'Section::::Abstract.'}]}]