After a few good long runs last week, I succumbed to temptation and ignored common sense by registering for The Middlebury Maple Run, a half marathon (13.1 miles) which attracted about 200 runners in its inaugural running last year, and filled up with 500 runners this year. I don’t usually write up road runs for this column, but my hunch is that a lot of the runners who enjoy the trails would also enjoy this event, which draws upon the support of a wide variety of local businesses, and is planned and staffed by many of my friends who are among the town’s diehard runners.