you have to be single to get on and by single meaning a solo rider.sometimes a group or family goes in this line but you will be split up.single rider (subject to closure) is meant to help maximize a ride capacity.sometimes there are odd number of riders and a single rider is place to fill in the vechicle.example in radiator racers the car capacity is 6 total rider 3 per row.say a group of two and a group of three are going one it leaves on spot open,in goes a single rider.single rider is avaiable in dl park for indiana jones and splash mountain. in dca its avaiable on soaring,goofys sky school,screaming, radidator racers,grizzley river run.signs in each will direct you where to enter and it can close at any time if too many single riders are in line. - pikarich  610.9 #178 10:05AM

The single rider line for splash mtn is at the exit, that one was hard to find for me. All the rest are easy to find, look for signs or ask a cm. - Twitterpated  230.9 #1228 10:46AM