Scoring: Accuracy counts before speed. A team that has 10 correct answers arriving after 3 hours and 20 minutes finishes ahead of a team with 9 correct answers getting back in two hours. This reduces the tendency of people to drive like maniacs. Getting the answer right is most important. Choosing your route to the locations is second-most. Driving fast only saves a few seconds here and there. Very occasionally a few seconds will make a difference in the final standings, but more often, when two teams are racing to plop down the envelopes on my table at the finish line, one of them will have more questions correct than the other anyway.
Details: The game can be modified to be done on foot, especially for young people. Downtowns have plenty of landmarks withing a short radius. Keeping teams together becomes a problem then and a source of contention.
The game can never be completely fair, so expect complaints that will have to be adjudicated on the spot, and some irritated people. Most teams will arrive adrenalised and absolutely giddy, however, requiring a half hour to calm down.
I design events to last no more than 4 hours, and tell people to just come in after that time. The better teams complete the series in about two hours. To make sure your puzzles are neither too hard nor too easy (or have mistakes), have a team test them before the competition date. Starting an hour before sundown seems to maximise the enjoyment. Four seems to be the best number per team. When I’ve done this as a fund-raiser for school or church groups, teams have had extra children or other relatives along, which doesn’t seem to do any harm. Young children are likely to get pretty bored with this, no matter how easy you make the puzzles.
Answers that have to be searched for once you get there are particular fun. Cemeteries are good for this, as are small parks and sports fields. Ambiguity is likely to lead to unfairness, however. People should know for certain when they have acquired the correct answer – that the sundial was dedicated in 1904, for example, because the plaque says Ded. 1904.
I usually design a mix of straight-ahead brute force puzzle-solving
Don’t send everyone along the same route, or people will just start following the better teams. Depending on the number of teams, I usually design 3 or 4 routes. It’s pretty easy to keep the mileage approximately the same with a minimum of attention by creating smaller loops and sending teams into them at different points. It is great fun, however, to make the first puzzle a longish one and send everyone to the same first destination. Then you can go there in advance after starting them off and watch them as they come in at least once. This was the only part my oldest son ever enjoyed that much, so he gladly volunteered to assist rather than compete.