Everyone working on UP tracks needs to bone up on Item 13 of the timetable (or whatever the equivalent General Order is for former SP territories).

They are looking for you to immediately reduce your speed to 35 mph and contact the train dispatcher. Stopping your train under the guise of "taking the safe course" will most likely get you a test failure.

Keep in mind that BNSF rules for detector failures are completely different from UP rules. Those of us who run on joint track have to keep that in mind. It can be very confusing at times.

Read and understand this rule and be prepared to comply with it.

Get in the practice of taking a measurement of your train when your head end goes by the detector. If you haven't gotten a readout by the time your rear-end has gotten 2000 feet past the detector, you need to be thinking about hitting the dispatcher call button.

Complacence is our biggest enemy. When you go over the same detector every day for years and never have a failure, it's real easy to convince yourself that it give a read-out.