  We have examined a topology of 21 public transport networks in Poland. Our
data exhibit several universal features in considered systems when they are
analyzed from the point of view of evolving networks. Depending on the assumed
definition of a network topology the degree distribution can follow a power law
p(k) ~ k^(-\gamma) or can be described by an exponential function p(k)
\~exp(-\alpha k). In the first case one observes that mean distances between
two nodes are a linear function of logarithms of their degrees product.
