They are Remote Street Light Monitoring installed by JCPL typically installed in a section of hazardous roadway. Depending on how far apart the Light poles are located, you will see them hanging from a module like the one posted or you can also see them installed on top of the light fixture with a small antenna similar to the one attached below (depending on the manufacturer). They are controlled by a larger module which will have a larger antenna (approx 18") typically mounted higher on a near by utility pole, above the phone/cable TV wires but below the level of a transformer.
Here is some info about the benefits/capabilities:
Remote Control and Monitoring of street lights can save energy, enhance public safety, reduce light pollution, reduce maintenance costs, provide valuable M&V information, and fixture health reporting to municipalities, states and other users. They can be used with LED, Induction, Plasma, eHID lighting, and standard HID.
A centralized command system can send astronomic time based instructions to individual or groups of street lighting to reduce energy consumption, when and where possible, during night time hours.
Demand responsive and adaptive, lighting can be dropped to lower levels through user selected, multi-level dimming scenarios, or based on input from traffic monitors or other systems and sensors. Revenue grade power metering through the use of Smart Meter chips is standard.
Additional public safety uses can include the ability for police or other emergency vehicles to interface through their onboard computers and raise light levels from nearby streetlights even higher than normal to aid in visibility for investigation, medical administration and incident clean up.
Gateway and software allow users to communicate with over a million system devices if a customer's network was that large. Standard units provide a 5 mile range to devices when mounted on poles twenty feet or higher.
Access to detailed fixture operating functions provides feedback regarding the health and performance of light fixtures for predictive maintenance and M&V. No longer will crews have to drive around at night looking for streetlight outages. Work orders are automatically generated.