You never really know who will refuse to play and who will play for six hours non-stop if allowed. Fortunately most people fit between these extremes.
If slot-racing is the only entertainment, a group of 20-40 will play enthusiastically for 1-2 hours. A game plan giving individuals 8 qualifying heats, followed by the top 8 drivers going through to a final set of 8 heats works well. This is one of the many game styles our bespoke computerised scoring greatly simplifies. The race director will choose the best option on the day.
Contractually we normally quote for up to three hours of game play. We are always happy to quote for extended running time.