The Scarborough RT (SRT or RT), officially Route 3 Scarborough RT, is a rapid transit line on the Toronto subway and RT system in Toronto, Ontario, Canada. The line is internally referred to as Route 3 (formerly route 603), but this number is not used by the public or shown on TTC maps and signs. In March 2011, it was announced that the Scarborough RT will be expanded westward along Eglinton Avenue to form the Eglinton Crosstown LRT line, while the current system will also be renovated and upgraded.