After two years of closure as a result of construction, Caltrain has reinaugurated its weekend train service with two weekends of free rides between San Jose and San Francisco. As the purpose of the construction was to enable its new “Baby Bullet” trains, the express service is debuting today with five runs each, morning and evening, stopping at six stations. Advertised time between SJ and SF is 57 minutes, 39 minutes faster. The track upgrades allow for a top speed of 79 miles an hour and added passing tracks for express routes.