The following example illustrates the problem treated in this paper: T
wo gas stations are located one after the other on a main road. A driv
er who needs to fill his tank sees the queue situation at the first st
ation but not at the second one. The driver estimates the expected wai
ting time at the first station, compares it to the conditional expecte
d waiting time at the second one, and decides which station to enter.
The second station is assumed to be on the driver's route so that no e
xtra cost is involved in choosing it. Is it true that the first statio
n always gets a higher share of the demand than the second one? We mod
el the situation in terms of queueing theory and answer the question.