As technology permeates every aspect of our lives, it’s tempting to embrace every innovation that promises to make life easier. One such technology is wired ultrasonic sensors and camera-based parking guidance systems with overhead red-green LED parking space indicators, designed to guide drivers to available parking spaces quickly. However, while these systems might seem beneficial at first glance, a closer inspection reveals that they are not as necessary as they might appear.

For parking and facilities managers, understanding the true utility and cost-effectiveness of these systems is paramount. This article aims to dissect the benefits and drawbacks of red-green overhead lights in PGS, ultimately determining whether they are a “must-have” or merely a “nice-to-have” feature.

Traditional wired PGSs often incorporate overhead red-green lights to indicate the status of parking spaces—red for occupied and green for available. Initially, these systems utilized individual space lights where vehicle detection sensors and lights were separate units. Modern systems, however, employ aisle-mounted lights that indicate the availability of multiple spaces on both sides of an aisle—typically one light per four spaces (two on each side). In these configurations, lights and detection sensors are often integrated into a single unit to optimize hardware and installation costs.

Although aisle-mounted systems offer cost efficiencies compared to individual per-space wired systems, they still require extensive ceiling support, conduits, and cabling infrastructure. Additionally, the aisle-mounting of detection sensors can negatively impact the vehicle detection accuracy of these PGS systems.

Red-green parking indicators are designed to enhance the user experience and shorten the search for an available parking space. Once a driver gets within a line of sight of these lights, they provide clear visual cues about the availability of parking spaces, potentially reducing the time spent searching for a spot. However, from an overall system’s perspective, these lights may be seen as merely an add-on and not as crucial as some might believe.

While entering and navigating within a typical garage in search of available spaces, drivers typically need to know two types of information:

• Which floor has the spaces they are looking for.
• Directional information (left/right/straight) to quickly get to the available spaces once on the target floor.

A system of red-green overhead lights alone is insufficient for providing navigational information due to the multi-level and complex layouts of typical garages. Drivers would struggle to see all the available lights and navigate effectively in a 3D space. Therefore, most systems still require Directional Message Signs (DMSs), also known as Visual Message Signs (VMSs), to direct major traffic flow within the garage.

A PGS system based on wireless sensors providing occupancy data and a pure DMS-based wayfinding approach can offer a superior user experience while keeping overall system costs lower than a typical red-green light wired system.

Providing a bigger and more functional set of directional DMSs positioned at all key intersections with both direction and number of regular and designated spaces (such as EV charging, ADA, and visitors) can provide drivers a very informative, intuitive, and efficient turn-by-turn wayfinding experience. This system also enhances driver safety by keeping their attention on the road, rather than frequently glancing up to locate and navigate toward a distant overhead green light.

Positioning smaller DMSs indicating the position and availability of special category spaces within the driving rows can further complement directional DMSs to efficiently direct such drivers, further reducing the incremental benefit of overhead lights over a DMS-based wayfinding approach.

While red-green overhead lights in PGSs can enhance the user experience by providing quick visual cues about parking space availability, their necessity is debatable. From a cost and efficiency perspective, a PGS system based on wireless sensors and comprehensive DMS-based wayfinding offers a more intuitive and cost-effective solution. By providing detailed directional information and space availability, such systems can better meet the needs of drivers without the extensive infrastructure requirements of traditional wired systems.

Parking and facilities managers should carefully evaluate the specific needs of their parking facilities and consider modern, cost-effective alternatives to traditional red-green light systems. Ultimately, the goal is to enhance the user experience while optimizing costs and efficiency—a balance that can be more effectively achieved with advanced DMS-based solutions.

We will continue exploring the subject of the pro’s and con’s of wired PGS with red-green lights in our upcoming “Hidden Costs of Red-Green Light PGS” blog post, stay tuned.

For more insights and to explore advanced PGS solutions tailored to your needs, contact us today. Let’s transform your parking management approach together.