Why isn't the subway image more passenger-friendly?
The subway image that you see on your monitor has been electronically
captured from the screen of one of the computers Muni uses to
control subway trains. The symbols and layout of this screen were
designed to be used solely by expert Train Control operators, not
for giving information to the general public. For dynamic train
information specifically designed for use by the public, please visit Muni's
Does this image show what is happening in the subway at the
time I download it?
Yes. A new subway image from the Central Train Control operator's screen
is captured every 5 seconds. This means that the image is at most
seconds old (plus the time it takes for your computer to download
it). Each time you click "Update Snapshot", the most recent
subway image is downloaded to replace your current one. The black
timestamp in the lower right corner tells you when the image you are
viewing was captured.
Why are some track sections dark red instead of the normal light
Tracks are shown dark red when they have been "closed" by a
Central Control Operator (CCO) or by the Train Control system.
Computer-controlled trains cannot move in a closed track section.
The short track sections that are seen above and below the main
track between Castro and Forest Hill stations are dark red because
they are kept “closed” during normal operation. It is common for
tracks to be closed for short periods by a CCO to allow personnel to
walk safely through the track or to force the Train Control system
to choose an alternative route for a train.
What do the small triangles along the track in front of a
The little triangles along the track show the route
that the train will be taking as it moves down the track.
Can the size of the image be changed?
No. It is permanently 1860 by 800 pixels and is based on the
resolution of the Central Train Control operator's screen, which is
permanently fixed at 1920 by 1080 pixels. The higher the user's
screen resolution, the smaller the image will appear on it. It will
not lose any sharpness, however.
Copyright © 2016 San Francisco Municipal Railway.