In 1998 she became a councillor for Amsterdam, for the Mokum Mobiel party "Mokum Mobiel" (Mobile Mokum), which she founded. Mokum Mobiel Party was mainly involved with traffic and parking problems of Amsterdam. A number of the Mokum Mobiel motions were passed by City Hall. During this period Gonny van Oudenallen fulfilled several positions within the City of Amsterdam: Vice President, Account Committee City of Amsterdam, Chairman, Ports and Finance Commission, a member of every City Council Committees, appointed by the Mayor to the inquiry procurement committee of the new metro line.