With that said, if a Mass that one considers appropriate isn't readily available (I "think" the obligation may not apply if one is 30 or more miles away, I'm uncertain of the exact criteria)
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No, St. Alphonsus says an hour's walk each way would probably not be long enough to dispense someone. I've seen moral theologians in the 20th century who said an hour's drive definitely is not long enough to dispense someone, and they say it would have to be at least an hour and a half's drive.
People claim an hour's drive was considered long enough to dispense someone from Mass before Vatican 2, but I've never seen a figure that low in any theologian that cites a time/distance.