Both, but we tend to use time here as well. Back when we lived on an Air Force base the nearest large city with things to do in was 45 minutes away. When we moved to another small town near there everything was still 45 minutes away. Now since I still live near the college I graduated from it usually takes 15 minutes to pull into work, but up to 45 on a bad day (ie the first week of school when everyone is still showing up or finals week). The actual distance is somewhere around 12 miles, but getting off of University Ave is more than half the time the drive takes.