  The network structure of an urban transportation system has a significant
impact on its traffic performance. This study uses network indicators along
with several traffic performance measures including speed, trip length, travel
time, and traffic volume, to compare a selection of seven transportation
networks with a variety of structures and under different travel demand
conditions. The selected network structures are: modified linear, branch, grid,
3-directional grid, 1-ring web, 2-ring web, and radial. For the analysis, a
base origin-destination matrix is chosen, to which different growth factors are
applied in order to simulate various travel demand conditions. Results show
that overall the 2-ring web network offers the most efficient traffic
performance, followed by the grid and the 1-ring networks. A policy application
of this study is that the branch, 3-directional grid, and radial networks are
mostly suited for small cities with uncongested traffic conditions. In
contrast, the 2-ring web, grid, and 1-ring web networks are better choices for
large urban areas since they offer more connectivity, thus allowing them to
perform efficiently under congested traffic conditions.
