Speed Zone in Park Ridge on Metra UP NW line?

I was wondering if there is some speed zone around the Park Ridge station on the Metra UP NW line. It seems that all the express trains slow down a little bit when passing through there. If there are speed zones on a line, how is it communicated? Also, are there warnings if the speed is exceeded or any automatic braking?

Thanks.

There is a permanent 55 MPH over that hump at Park Ridge. Its found in the employee timetable along with a other speed restrictions. There should be permanent speed board 2500 ft ahead the restriction to warn the Engineer. As of right now there isn't anything in place if speed is exceed...but that will eventually change with PTC in the future.