Road Trip Planner

Creates a road trip on Stopful, or updates one plotted earlier, and returns an interactive map of it — adding, removing, reordering or renaming stops, changing nights, dates or party size, and redrawing the route. Renders a multi-stop driving route as an interactive map and returns a link to it, plus an inline map in clients that support one. Takes a list of stops in driving order, each with a place name, optional decimal lat/lon and number of nights; a stop without coordinates is geocoded from its name, and coordinates that fall far from where the name resolves are reported back in the result. Accepts an optional trip name, start date, party size, and a day-by-day itinerary that becomes a day view over the map. The map shows per-leg drive times and distances and an estimate of what the trip will cost before anything is booked, and is editable: the traveller can drag a pin to move a stop or drag the route to add one, and their changes are saved to the trip. Covers road trips and other multi-stop routes; a single destination or a route with no stops to draw has nothing to render. The result contains the map link, the trip as structured data, and the trip's `id` (see the `id` parameter for updating an existing trip).