Passage: Canberra is a planned city and the inner-city area was originally designed by Walter Burley Griffin, a major 20th-century American architect. Within the central area of the city near Lake Burley Griffin, major roads follow a wheel-and-spoke pattern rather than a grid. Griffin's proposal had an abundance of geometric patterns, including concentric hexagonal and octagonal streets emanating from several radii. However, the outer areas of the city, built later, are not laid out geometrically.Lake Burley Griffin was deliberately designed so that the orientation of the components was related to various topographical landmarks in Canberra. The lakes stretch from east to west and divided the city in two; a land axis perpendicular to the central basin stretches from Capital Hill—the eventual location of the new Parliament House on a mound on the southern side—north northeast across the central basin to the northern banks along Anzac Parade to the Australian War Memorial. This was designed so that looking from Capital Hill, the War Memorial stood directly at the foot of Mount Ainslie. At the southwestern end of the land axis was Bimberi Peak, the highest mountain in the ACT, approximately 52 km (32 mi) south west of Canberra.The straight edge of the circular segment that formed the central basin of Lake Burley Griffin was perpendicular to the land axis and designated the water axis, and it extended northwest towards Black Mountain. A line parallel to the water axis, on the northern side of the city, was designated the municipal axis. The municipal axis became the location of Constitution Avenue, which links City Hill in Civic Centre and both Market Centre and the Defence precinct on Russell Hill. Commonwealth Avenue and Kings Avenue were to run from the southern side from Capital Hill to City Hill and Market Centre on the north respectively, and they formed the western and eastern edges of the central basin. The area enclosed by the three avenues was known as the Parliamentary Triangle, and formed the centrepiece of...

Question: what was the main function of the smaller suburbs and town centers?
focus of commercial and social activities