A park using a single-rider line offers guests a chance to wait for a significantly shorter length of time in exchange for not necessarily being able to experience the attraction with others in their party or from a desired seat (e.g., the front row of a roller coaster).
In a memo dated July 31, 1958, Walt Disney directed the Disneyland Operations Committee to "Establish a special line for single riders, with the request that they double up.
[3] Because single rider lines are normally used to fill up otherwise empty seats, they have no direct, negative impact on the main queue.
In most cases, a guest using a single-rider line must meet the normal rider requirements for the attraction and must be able to ride in any empty seat presented.
[5] Although not specifically a single-rider plan, some parks provide provisions for parents of children who are too small or young for an attraction.