Umbral Truths: A tl;dr Eclipse "AAR"
tl;dr: "Too long; didn't read" - often applied to "wall of words" posts in forums. I'll keep this a short, sweet primer!
Eclipse Planners: Three Things to Make or Break You
Transportation
This is the big headache - as people stream into your community, you'll find roads busier than normal, and those intersections that are a pain on a normal day (you know the ones, you take a 3 min detour to avoid them during busy times) will become a NIGHTMARE leading up to and immediately after the Eclipse.
Traffic planners, the Road Departments, and Law Enforcement for localities all need to sit down and come up with a solid, viable plan to move people around, especially those who are unfamiliar with the area! You'll want to consider:
One-way roads in congested areas to ensure smooth traffic flow
Temporary stoplights for busy 4-way intersections
Readerboards to direct people to desired locations
Temporary road closures to protect infrastructure or sensitive areas or allow "bypasses" for public safety/public works to get around heavy traffic to respond to issues
How do we avoid the "mass exodus"? Can't we get them to stay another day?
Realistically? You probably can't, not enough to make a significant difference anyway. Like 2017, this eclipse will be on a Monday during the school year. People might take the day to be there, plus a day or two for return travel, but the reality is they will have to get back to work and/or school. Make efforts to retain people, sure, but don't expect they're going to "slowly filter out". My experience in 2017, from Dixie Pass at 5,000ft on Highway 26 in Eastern Oregon - the Centerline of Totality - as soon as Totality was over, car doors were slamming and people were flooding the highway. Hours of backup and L.A.-style traffic jam ensued all over the area on Highways 26 and 395. I welcome folks to try to stop that from happening, but I'm not optimistic about your chances.
Toilets & Sanitation
25+ years in public safety with the attendant dark humor leads me toward making an obligatory "crappy day" joke. Let's stipulate it as made and move on - because this really is NO JOKE.
Having spent 14 years with the US Forest Service in Fire/Emergency Management, I've been part of numerous "Fire Camps" where hundreds to thousands of firefighters and support personnel eat, sleep, and receive equipment, supplies, and briefings, usually staying for 14-21 days at a time. "Camp Crud" is a serious issue even in clean well-maintained camps, and you don't want your Eclipse-goers and event attendees remembering your town as "that place we all got sick for the Eclipse".
Carefully consider your needs, not just for porta-potties but handwashing stations as well. Washing your hands is vitally important to preventing "the crud" or more serious disease transmission, so make handwashing stations a "must" along with your porta-potty order.
There are numerous websites that give you formulas or a calculator for how many porta potties you'll need, they're easily searched by something like "how many porta potties for an