The trolleybus system was opened in 1992, using a fleet of 65 articulated trolleybuses built by Czechia's Škoda. This was the first trolleybus system in Iran. In 2005, trolleybuses were operating on five routes, all starting at Imam Hossein Square. Two routes running northeastwards operate almost entirely in a segregated busway located in the middle of the wide carriageway along Damavand Street, stopping only at purpose-built stops located about every 500 metres along the routes, effectively making these routes trolleybus-BRT (but they are not called such). The other three trolleybus routes run south and operate in mixed-traffic. Both route sections are served by limited-stop services and local (making all stops) services. A 3.2-kilometer extension from Shoosh Square to Rah Ahan Square was opened in March 2010.