After its establishment, the Third District Maintenance Construction Office consists of two sections and three offices: Construction Section, Maintenance Section, General Affairs Office, Accounting & Statistics Office and Personnel Office. Moreover, there are three construction sections: the first section with Gangshan Station, Fongshan Station and Cishan Station (established on October 1, 1955); the second section with Hengchun Station (established on February 15, 1949), Pingtung Station & Fonggang Station (established on September 16, 1955), and Donggang Station (established on April 1, 1969); and the third section with Dawu Station (established on March 1, 1955), Chenggong Station (established on December 1, 1955), and Lijia Station (established on June 7, 1976).

The fourth and fifth construction sections were established on November 1, 1972, consisting of four stations (Taoyuan Station, Baolai Station, Tianchih Station and Siaolin Station) and three stations (Guanshan Station, Wulu Station and Siangyang Station), respectively. Besides, in order to carry out temporary construction projects, a heavy machinery brigade was organized on April 16, 1973. The sixth construction section was established on October 1, 1978, and the seventh construction section was established on February 12, 1979; Hengchun Station and Fonggang Station which were previously subordinate to the second section were reorganized into the seventh section. In response to the traffic improvement and widening project in Kaohsiung and Pingtung areas, Fonglin Branch and Pingsin Branch were established on March 1, 1980; they were then dissolved in tandem in July 1993 due to the completion of the said project. On April 1, 1991, the heavy machinery brigade was dissolved due to operational streamlining, while Cishan Branch was established on March 1, 1991 for the widening and improvement project on Provincial Highway No. 3 and County Highway No. 184 in Cishan. Liling Branch was established in September 1992 for the widening project on Liling Bridge, and Dongbin Branch was established in December 1993 for the widening project on East Coast Expressway (Provincial Highway No. 11).

According to the resolution attached to the general budget proposal of the Provincial Assembly in 1996, a number of ministries, departments and bureaus subordinate to Taiwan Provincial Government named their divisions and offices by numbers, which were easily confused. As a result, it was recommended that these divisions and offices be renamed. The Office, based on the aforesaid principle, renamed its first to seventh construction sections in terms of location on April 1, 1997: Kaohsiung, Chaojhou, Taitung, Jiasian, Guanshan, Penghu and Fonggang, respectively. Furthermore, Wang-an Branch was established on November 1, 1999 to carry out the construction project on Penghu Great Bridge between Wang-an and Jiangjyun, as well as two collector/distributor roads.

Since its establishment in 1949, the Office has undergone several organizational expansions due to operational needs. The Office now comprises: Construction Section, Maintenance Section, Land Section, Equipment & Supplies Section, General Affairs Office, Accounting Office, Civil Service Ethics Office and Occupational Safety Office, as well as a maintenance workshop, seven construction sections and four branches. Upon completion of the Constitution amendment by the National Assembly on July 21, 1997, Article 9 on the “Reorganization of Taiwan Provincial Government” was added to the Amendments to the Constitution of the Republic of China. Hence, the Directorate, originally under the charge of Taiwan Provincial Government, was subordinated to the Central Government on July 1, 1999 due to the organizational streamlining of the Provincial Government. The Directorate has been under the direct administration of the Ministry of Transportation and Communications since then, and the Office was renamed the Third District Maintenance Construction Office, Directorate General of Highways, M.O.T.C., accordingly. After the General Provisions on the Organization of District Maintenance Construction Offices were proclaimed by the President on January 21, 2002, the Office was officially named the Third District Maintenance Construction Office, Directorate General of Highways, M.O.T.C., on January 30, 2002.