This article relies excessively on references to primary sources. Please improve this article by adding secondary or tertiary sources. Find sources: "SelTrac" – news · newspapers · books · scholar · JSTOR (April 2008) (Learn how and when to remove this template message)

SelTrac is a digital railway signalling technology used to automatically control the movements of rail vehicles. It was the first fully automatic moving-block signalling system to be commercially implemented.

SelTrac was originally developed in the 1970s by Standard Elektrik Lorenz (the "SEL" in the name) of Germany for the Krauss-Maffei Transurban, an automated guideway transit system proposed for the GO-Urban network in the Greater Toronto Area in Canada. Although the GO-Urban project failed, the Transurban efforts were taken over by an Ontario consortium led by the Urban Transportation Development Corporation (UTDC), and adapted to become its Intermediate Capacity Transit System (ICTS). This technology was first used on the SkyTrain network in Vancouver, British Columbia and the Scarborough RT in Toronto, Ontario.

SelTrac was primarily sold and developed by Alcatel, through a subsidiary. SelTrac is now sold by Thales from their Canadian unit, after it purchased many of Alcatel's non-telephony assets.


SelTrac uses the twisted-loop concept developed by Siemens in the 1950s.[1]

Data communication is provided with either low frequency inductive loop or a high bandwidth, open-standards wireless system incorporating spread-spectrum radio technology.[2]


SelTrac is installed in many railways around the world,[3] including the following:

SelTrac Incidents


  1. ^ [1], see LZB
  2. ^ "Thales SelTrac CBTC Brochure" (PDF). Thales Group. Retrieved 21 March 2015.
  3. ^ "SELTRAC CBTC, COMMUNICATIONS-BASED TRAIN CONTROL FOR URBAN RAIL". Thales Group. Archived from the original on 2 April 2015. Retrieved 21 March 2015.