15 miles. It takes an hour from the time I leave the house until I get to work by taking the bus/trolley. It takes an 1 hr-1hr 15 mins by bus/trolley (or more if I miss the trolley) on the way home and add 10-15 mins to that if I ride home.

Saturdays, public transportation won't get me to work on time so I can drive the 15 miles to work in about 20 minutes or I can ride in using a flatter 12 mile route. I have yet to test ride this route so I'm not sure how long it'll take me, but I'm estimating 1hr-1hr 15 mins.