Dissecting the Intersection

In a study by the California Energy Commission, traffic intersection lights experience eight to 10 power outages during one year. With each one, intersections are left uncontrolled, posing real risks to the public. Dennis Bennett explains how we can improve intersection safety.

“Changes in traffic light technology from incandescent lamps to LED lamps has reduced power consumption”
-Dennis Bennett

A temporary solution to losses of power to traffic lights has been to rely on drivers to use a four-way stop procedure. This helps to a degree, but drivers can become irritated and aggressive, which can lead to incidents and accidents. Another solution is to have a traffic control officer on-site to direct traffic at the intersection but this solution only works based on the availability of resources and the time and distance required for a person to reach the intersection. Some jurisdictions have used generators to temporarily supply power to intersection controls, however, this can be costly because both fuel and manpower need to be supplied.

Changes in traffic light technology from incandescent lamps to LED lamps has reduced power consumption, making it possible for intersections to include battery backup power solutions to keep lights operating during outages and disruptions. Still, this inclusion is often overlooked because of the challenging installation environments, lack of understanding of the solutions available and the incremental cost of adding battery backup to a system.
 
A UPS (uninterruptible power supply) differs from a battery backup system as it offers more sophisticated power filtering and control, faster transfer times and advanced monitoring and communication capabilities. In the past, the only UPS solutions available were standard, off–the-shelf solutions used in offices and data centers. Typically they only offered enough run times to enable the graceful shut-down of servers and other electronic devices and were not designed to work in outdoor environments that saw extreme temperatures, dust, or road vibration, nor did they provide run times necessary to sustain services in the event of lengthy outages.

The ideal solution now is a ruggedized outdoor UPS. This offers long run times and is designed to withstand extreme temperatures and environments where the shaking caused by cars, trains, trucks, buses or planes can not interfere with its operation. Often these solutions include ruggedized UPS control modules that manage and filter the electricity, specialized batteries that provide dependable service regardless of environmental conditions (with optional heater mats to keep batteries warm in colder environments) and outdoor rated enclosures (NEMA 3R rating) protecting the UPS system.

Yet integrating a UPS into every traffic system is not recognized as a standard requirement in many areas, and during the initial installation of an application, the need for protecting critical loads is often forgotten until a power disturbance occurs. Then the impact can be catastrophic: systems stop, traffic flow is impacted, revenue is lost, accidents can occur. However, many systems owners don’t realize retrofitting a UPS into existing traffic systems can be easy and cost effective even though designing, installing, and maintaining transportation systems is costly.

Cities, counties and states are constantly challenged to reduce costs as traffic systems are publicly funded and under strict budgets. Many planners consider a UPS as a costly option, but when they realize the direct and indirect costs that result from a failed traffic signal, the cost of including a UPS is easily rationalized.

Traffic systems can operate flawlessly when good, clean, uninterrupted power is available. When power fluctuations, brownouts and complete power outages occur, and systems come to a quick halt. There is an urgent need for servicing, resources may be needed to direct traffic, there are economic and environmental impacts, commuters are left to manage through the disruption, accidents can occur, and safety can be at risk. UPS systems designed for traffic applications should therefore be the first consideration in improving intersection safety.

Dennis Bennett is the National Sales Manager for Traffic Solutions at Alpha Technologies and has focused exclusively on the traffic market for the past five years. As a graduate of Ohio Institute of Technology (Devry), Dennis has worked in the Power Protection and Battery Backup industry for over 30 years.

Dennis Bennett
National Sales Manager
Alpha Technologies Ltd.
E: info@alpha.ca