The company operates both coach, bus, charter and school routes, as well as some truck and garage services.

TrønderBilene runs three town bus services: Buster in Steinkjer, Blåmann in Levanger and Verdalsøra, and Elgen in Namsos.

TrønderBilene is an operator of scheduled, charter and school buses, as well as trucks and mechanical services.

The main areas of operation are the districts of Innherred, Namdal and Fosen, and the islands of Hitra and Frøya.

The scheduled bus transport is on contract with Trøndelag County Municipality based on concessions with subsidies.

The company also operates urban buses in four towns in Trøndelag: Buster in Steinkjer, Blåmann in Levanger and Verdalsøra, and Elgen in Namsos.

The express bus from Namsos via Steinkjer to Trondheim operates as part of NOR-WAY Bussekspress.

Twenty-four people work at the garages, and the company sells services to other bus and truck operators.

The route started at Steinkjer Station, where it connected to the Hell–Sunnan Line that had opened three years earlier, and ran to the south shore of the river Namsen, where a ferry took passengers to Namsos.

The company bought two seven-seat Rex Simplex cars, that made the 50 kilometres (31 mi) route in two and a half hours.

[6] Inderøy Automobillag was founded in 1917, and operated a route from Røra Station on the Hell–Sunnan Line via Straumen to Utøy.

[6] The idea to have a county-owned bus company was launched by engineer Emil Astrup, who was head of the Public Roads Administration in Nord-Trøndelag.

He wrote a letter in 1918, where he stated that it would be more operationally efficient and easier to coordinate traffic if the bus routes in the county were merged into a single entity that was controlled by a political body.

Negotiations with the four incumbent operators started in 1920, and agreements were made whereby the county would purchase them for 560,000 kr.

The routes were largely planned to supplement the railway line, that would operate as the main artery north–south through Innherred.

During 1920, there was a strike in the Norwegian State Railways, and Fylkesbilene had to operate a post car on the route from Trondheim via Steinkjer to Sunnan.

The company's first head office was at Grand Hotell in Steinkjer, a block away from the railway station.

[10] At the break-out of World War II in Norway on 9 April 1940, all the company's buses were taken over by the armed forces.

The same year, the company introduced a direct service between Verdalsøra and Levanger, that previously had only been served by the railway.

[15] The same year, the company established a route from Vanvikan via Leksvik to Mosvik and onwards to Steinkjer.

[17] The company's main depot was opened on 25 November 1969 outside Steinkjer, and cost NOK 2 million.

[18] In 1981, Fylkesbilene bought Arne Bruem's concessions and buses that operated the town bus in Steinkjer.

The same year, the company introduced the Environment Card monthly pass, that halved the price.

[26] The work to establish a charter division began in the early 1980s, when the company realized that it had a large amount of idle capacity during the daytime, in the evenings and in the weekends.

[30] Three companies bid for part or all of TrønderBilene: Fosen Trafikklag, Hemne og Orkladal Billag and the consortium NT-Buss, led by Namsos Trafikkselskap.

[32] On 20 January 1999, the county council approved the Fosen bid, who paid NOK 29.7 million for the company.

[36] In 2002, the company applied to start a coach service from Trondheim to Bodø in cooperation with SB Nordlandsbuss, and concession was granted by the Ministry of Transport and Communications the following year.

[44] In January 2007, TrønderBilene increased their ownership in Namsos Trafikkselskap from 8.7 to 20.7%, becoming the company's second-largest owner after Helgelandske.