Gravity Forms
+ Event Carpool Matching

Sharing rides to a school open day, a tournament or a summer festival saves parking, money and stress, but a carpool list on a noticeboard or in a group chat quickly breaks down: nobody has time to match thirty drivers with forty riders, everyone sees everyone's phone number, and two families end up promised the same seat. The Gravity Forms Event Carpool Matching add-on turns one sign-up form into a carpool that runs itself.

Drivers say how many seats they offer and riders how many they need, with their area (postcode and town, or a map pin) and a departure window for the trip to the event, the trip home or both. Each person gets a private page by e-mail with people going their way, ranked by area, time, free seats and preferences such as a smoke-free or women-only car. A rider requests a seat or a driver offers one; the other person accepts or declines. Contact details are shared only after both accept: until then people see a first name and initial, a town and postcode area and a time window.

Seats are held the moment a ride is accepted, with a database update that cannot give the last seat twice. Cancelling releases the seat and tells the other person, and a reminder goes out before departure. The organiser board shows seat totals per trip and direction, who is still waiting with their best drivers, manual match proposals that both people must accept, and a CSV export. Carpool data is deleted automatically after the event. All matching runs on your own server, with no map, routing or geocoding service. Participants arrange their trips directly with each other. For Gravity Forms 2.9 and newer.

Each entry of the sign-up form becomes a carpool sign-up with one leg per direction. For every driver and rider on the same trip and leg, the add-on checks the area (straight-line distance when both have coordinates; otherwise the UK-style outward code or the first characters of the postcode, then the town name with accents, punctuation and "Saint" / "St." normalised), the overlap of the departure windows, the free seats and the preferences, and scores each possible match from 0 to 100. The personal page, opened by a link signed with a per-person secret, lists the best matches and the person's own requests. When both people have accepted, the seats are held with a single conditional database update on the driver's and the rider's seat counts, so parallel acceptances can never take the same seat; only then are the contact details shown and e-mailed to the two of them. An hourly scheduled task sends the reminders before departure and deletes each trip's carpool data after the number of days you set. Everything happens on your own server — the add-on makes no outside HTTP request beyond the licence and update checks.