Sea-Tac's existing signalling system was replaced by a Bombardier CITYFLO 650 solution.
The CITYFLO 650 solution supplied includes the EBI Com radio block centre, EBI Cab ATC onboard equipment and the EBI Screen control room and supervisory system.
Other improvements include upgrades to central control, power distribution and other equipment. Using the Bombardier CITYFLO 650 overlay capability, full passenger service was maintained during the replacement and upgrade programme.
In total, this driverless system covers 3 km of track with up to 22 vehicles passing through 8 stations.