Transport and Telecommunication Institute (TTI) (Latvian: Transporta un Sakaru Institūts, TSI) (Russian: Институт Транспорта и Связи, ИТС) (previously known as RCAII and Riga Aviation University) is the largest university-type accredited non-state technical higher educational and scientific establishment in Riga, the capital of Latvia.

[1] Main directions of academic activities include electronics and telecommunications, information technology and computer science, economics, management and business administration, transport and logistics.

In 1938–39, a status of this educational establishment was changed due to the prevailing number of students and listeners raising the level of their skills.

By its 80th anniversary the RAU was the largest higher school in Latvia holding a third place in the ranking of the educational establishments in the country.

On 6 September 1999, the joint stock company "Riga Aviation University" had been registered and from October of the same year it was renamed into the Transport and Telecommunication Institute.