After leaving school in the 1890s, William George Toop Goodman joined the London engineering firm of Poole & White. In 1884 he moved to Australia, and in 1895 he installed the first electrical plant at the Mount Lyell mines in Tasmania. Next Goodman went to New Zealand to work for Noyes Brothers on the construction, in Dunedin, of New Zealand's first electric tramway. He remained in Dunedin for some time and in 1903 became its chief electrical engineer.

In 1907 Adelaide established its Municipal Tramways Trust (MTT) and appointed Goodman as chief engineer, then general manager a year later. He remained in both posts until he retired in 1950. During this time, William Goodman established an electric tramways system in Adelaide (1907) and Port Adelaide (1917), a new power station, increased the number of MTT buses in operation, took over the management of the Adelaide-Glenelg railways (1929), and later replaced Port Adelaide's trams with double-deck trolley buses (1938).

During his forty-two years of service with the MTT, Goodman also held many external posts including: Federal government agent to research advances in munitions production and visited factories in Britain, Europe and the United States of America; member of the royal commissions into transport (Auckland) and South Australian railways; member of the joint Commonwealth-States inquiry into the Hume Reservoir; councilor of the University of Adelaide for over forty years; chair of the South Australian Housing Trust (1937-1944) which provided locals with low-rental accommodation and member of the Metropolitan Omnibus Board.

William Goodman's efforts were rewarded in 1932 when he was knighted, and in 1945 when he received the Peter Nicol Russell Memorial Medal, the career achievement award from the Institution of Engineers Australia.