We introduce an extension of the M/M/1 queueing process with a spatial
structure and excluded- volume effect. The rule of particle hopping is the same
as for the totally asymmetric simple exclusion process (TASEP). A
stationary-state solution is constructed in a slightly arranged matrix product
form of the open TASEP. We obtain the critical line that separates the
parameter space depending on whether the model has the stationary state. We
calculate the average length of the model and the number of particles and show
the monotonicity of the probability of the length in the stationary state. We
also consider a generalization of the model with backward hopping of particles
allowed and an alternate joined system of the M/M/1 queueing process and the
open TASEP.Comment: 9 figure