I have a traffic signal that I have left over from a recent installation and I am interested in using it in my gameroom. I would like to make it light up one lamp at a time (Red, Yellow, green) and then I would like for it to flash all three lamps simultaneously about three times then repeat the sequence. The lamps are 120 Volt lamps so line voltage would be best. Any ideas?

Yea, program a PIC microprocessor.
These guys Comfile Technology Inc. make a Basic programmable processor.

The IDEC smart relay IDEC SmartRelay l IDEC Products
Or equlivelent mini-PLC A number of companies make similar devices.
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They are all ideas. All with various costs. Development, skill level and the ability to change or modify the design.

The smart relay or BASIC programmable processor are probably the best two options.
Generally, you would use an I/O module to optically isolate the AC line from the processor and with the lots of operations, you would use solid state relays for the output rather than relays. You could reprogram the processor when you got tired.

With the smart relay and the HMI (Human Machine Interface) you could select different programs to run. Not that you couldn't do it with the BASIC version.