The river path is closed for two weekends. You posted a pin in the club chat. Half the Saturday group does not use that chat. The other half thinks you meant the long loop. At 7:30 you will have people at two starts.
A route change is a decision with a start line. People will go to the last place they remember unless you put a closed choice in front of them.
Write the route in words
"I need A or B for Saturday 7:30: keep the usual park loop (5 miles, pavement, start at the south fountain), or move to the canal towpath (6 miles, packed gravel, start at the lock). Answer by Thursday evening." That is a decision.
Write for a cold runner. The person who last came in autumn does not hold the pin. Give start, miles, surface, turnaround, and the fact that forced the change — a closure, a flood, a race taking the path. Cut the thread about who prefers hills.
No GPX. There is no file path. If the club already hosts a map, name that page. A typed address in the note is not something a mail client should turn into a surprise click.
State your lean. "I recommend the canal. I keep the park if two people say they cannot do gravel." The second sentence is the disconfirmer.
Who votes
Name the shape. If the officers pick the route, it is their decision. If you want a read from Saturday's regulars, it is an opinion, and you still pick. Mislabelling those is how people feel ignored after they wrote a paragraph.
Write to the people who will stand at the start, one address at a time. The alumni list is not the Saturday group.
They need no account. The mail is the product. They reply from the mail or the page. You approve the wording. The club's assistant does not move the start as you.
If you use Claude and a co-organizer uses ChatGPT, members read one briefing. That is enough.
Do not put a private nickname in the package. Use the names people run under.
What a sufficient reply is
"B." "A — I cannot do gravel." "B if we keep it to 5." One line. Say that is enough.
Then a default. "If I do not hear by Thursday evening, we meet at the south fountain and I will have a printed note about the canal for anyone who wants it." A default that leaves two starts is how you split the club in the dark.
What this is not
It is not a training plan. Pace groups and who leads are a different ask, after the start is settled.
It is not medical advice. You can state the surface and the miles. You cannot tell someone whether they should run.
If your assistant already has last Saturday's note, let it draft the two options. You read the starts. Then people can answer before they lay out clothes.