My boyfriend is really into biking & has been trying to get me out for a while. I just got a new road bike & was looking for good beginner trails with no traffic. I found a couple good ones - in Fremont there is a 30 mile bike path with no cars called the "Alameda Creek Trail" (don't be confused it's not in alameda). Flat & runs along a creek, really pretty & a good place to get comfortable on your bike. Also, found a great bike trail in Healdsburg - Dry Creek Valley. Approximately 25 miles. A vineyard tour with a few rolling hills, not a lot of cars.