The short answer is: Not really, but with a couple modifications it can be done.
The longer answer is: Portfolio Manager is not set up to track street lighting or traffic lights for a city or town. Portfolio Manager tracks energy use at the building level, but there is no "building" associated with street lighting. There is no square footage, no workers, no computers, ...
As a result, the majority of metrics in Portfolio Manager will be misleading and/or inaccurate. All the intensity metrics will be inaccurate because there is no square footage for a streetlight.
But, if you still really want to use Portfolio Manager to track your street or traffic lights, you can. You'll want to track their "Source Energy Use" and "Total GHG Emissions." Simply add a property as the "Other" property type and enter a Gross Floor Area of 1 sq ft. Then enter the energy use for the lights and you can track the energy use and GHG emissions over time for this "property." You can also use the "Property Notes" section on the Details tab to capture information such as the number and type of lights. Remember, “intensity” metrics incorporate square footage and should be ignored.