Bay seniors won’t believe Marin will get a rail line until the day actual trains race past commuters on 101. Meanwhile skeptics can enjoy the bike tunnel opened between San Rafael and Larkspur Landing, a preview of the supposed route to come. It’s not long, just 1100 feet but the Cal Park Hill Tunnel cuts 15 minutes off biker’s trips. Open seven days a week from 5am to 11 pm. Meanwhile down the coast the Devil’s Slide Tunnel is slated (cross your fingers) to open at the end of the year, freeing the old,slide-prone section of Highway 1 for hikers and cyclists.