Back in 1996, when Lyman Jordan, founder of Race Resources, wanted to create a race that would go between two metro stations about 10K apart outside D.C., the route he planned crossed through multiple towns and counties, involved transit agencies and police, and ultimately two him two years to get approved and established. “The traffic plan was 100 pages,” he said, and included 2,000 orange cones.

But now the Pikes Peek 10K is a popular race that’s been going every year since. It was worth the headache.

While many of the issues with creating a course are the same no matter how big or small your race is, once you start to crack 500 runner...