Model railroad signals, once installed on a layout add not only visual animation, but actually become the rules that govern your train operations. Signals give you a clear visual indication of what is happening on the tracks ahead of or behind a train. As in prototypical railroading, a fully operational signal system on your layout operates much the same way utilizing train detection to automatically determine what aspect or colors a signal head should display.
Having an operational signal system on your custom model railroad is an exciting aspect of the hobby that's growing rapidly as new hardware is always being developed by someone. If you are intending to use a computer, software such as JMRI makes it easier to install and configure.
A signal systems can be as simple as showing turnout position or as complex as train detection for full signal automation. Some examples of signal system installations that I've built into custom layouts are detailed in the photos below.
Modern BLMA signals are shown here governing the movements through this crossover section on the HO Scale Salt Lake Corridor layout. The signals change their aspect or color automatically when a train enters the isolated blocks of track on either side of the crossover. Since they are protecting train movements through the crossover, the signals also show what is happening in the first 3 track blocks on either side of the crossover by displaying either a red, yellow or green aspect/color. Installing this signal system utilized the Digitrax BDL168 rail current detection board, SE8C signal logic board and JMRI computer software to make work. Your rolling stock needs to have metal wheel sets with resistors on them to be detectable.
The Poco Grande N Scale layout shown above features a 3 aspect/color signal system that protect the crossovers and any diverging routes from or onto the double track mainline in both directions of travel. This signal system also is fully automated. It too uses rail current block detection which feed information to a custom made signal logic board that processed the signal commands to change the necessary signal colors. This signal system was independent from the DCC system and did not require a computer to handle the signal logic. The signal system and all searchlights signals were designed, built, and installed by Custom Signal Systems in Salt Lake City, UT.
These scratch built block signals control train movements on the HO Scale Parker Subdivision layout. If a particular signal is needed that can't be found commercially, as part of the larger project, I can scratch build signals to match prototypes as needed.
Another type of signal found on railroads is the grade crossing signal. On the Poco Grande N scale layout two pairs of NJ International crossing gates were modified with micro LED's on the gate arms and were wired to flash prototypically with the mast mounted crossing lights. Additionally, these crossing gates were activated when a train was detected on either side of the crossing. There was a working bell circuit as well. This crossing gate's modifications and electronics were done by Custom Signal Systems in Salt Lake City, UT.
Yet another qualifier as a signal system that has been requested on custom layouts is traffic lights. The ones shown here are from Berkshire Junction and are shown in N scale. The mast signals were planted on all four corners of an intersection and included the hanging four-way traffic light strung between two telephone poles. They were automated with a traffic light circuit timer so they were able to change colors as a real traffic light does. You can adjust the length of the traffic light cycle as well. Always a very cool feature and available option.