The Rooftop Down Approach to PGS 1

The Top-Down Approach to Parking Guidance Solutions

Why Accurate Data from the Roof is Key to Garage Efficiency


Parking garages have long been a convenient necessity in our busy world, offering secure and weather-protected spaces for vehicles in high-demand locations. Like any commercial real estate, they can also offer attractive returns on investment. However, the efficient management of these facilities is often a complex task, especially during peak hours. The clue to effective parking garage management lies in an unexpected place – the rooftop or highest garage level.

This blog post will explore the importance of accurate real-time rooftop parking occupancy. With recent advances in wireless parking guidance technologies, this is often a “low hanging fruit” for boosting asset efficiency and customer experience with minimum investment.

A Brief History of Parking Guidance and Occupancy Monitoring Systems

In the past, parking guidance and occupancy monitoring in garages relied heavily on wired, ceiling-mounted sensors. These technologies were revolutionary in their time, providing a leap forward in efficiency by allowing the tracking of occupied and vacant spaces in real time.

However, these wired systems had their limitations. Their requirement for ceiling installation presented a significant challenge for rooftop parking. With no ceiling to mount the sensors or run the wiring, the rooftop became a blind spot in the occupancy monitoring network, resulting in an underserved area that traditional technologies could not effectively manage.

This limitation underscored the need for innovative technology to decipher rooftop parking occupancy. As we will elaborate below, from a business standpoint, monitoring the rooftop is arguably the pivotal function of a parking guidance system.

Understanding the Parking Flow

While there may be unique garages with complex traffic flow patterns, it is almost universally true that garages fill up from the ground level to the top. Cars typically enter on the ground level and ascend in a spiral pattern from one level to another until they find an open parking spot. From a practical standpoint, drivers also prefer to park their vehicles under cover to protect them from the weather, and favor a shorter drive and lower floor parking.

If the driver makes it to the rooftop without finding a parking space, it is highly likely that the lower floors are full. When a driver gets to the rooftop and finds it fully occupied, they have to circle back down, and if a spot opens up on their way, they’re likely to take it.

This explains a simple rule of thumb many garage operators know from practice: a full rooftop generally means a full garage.

The importance of knowing when the garage is full cannot be understated – both from a facilities manager and a customer perspective.

The Unseen Spaces

The architecture of many parking garages can sometimes lead to misconceptions about their occupancy. Garages often have open designs without walls, giving a quick visual snapshot of the lower levels to those passing by. This can create an illusion of the entire garage being full when it might not be the case.

If the lower levels are packed with cars but the top floor is relatively empty, a passerby might assume the whole garage is at capacity. However, this isn’t necessarily true – the top floor could still be brimming with available spaces. It’s just that these spaces aren’t immediately visible from the outside (or by traditional wired parking guidance systems). And from a customer perspective, it may be too risky to take the chance of driving into the garage and going all the way to the top just to see if there are available spaces.

The Top Priority of Real-Time Data

The need for real-time data becomes clear when considering the potential loss of revenue and customer experience. If managers inaccurately display the garage as full while there are still spaces available on the roof, they will be turning away potential parkers.

Similarly, if numerous customers drive into a crowded parking garage, navigate multiple levels to the top, and then descend again, only to discover that the garage is full and no accurate occupancy data is available to save them time, they will likely feel less than happy and may consider using a different facility next time.

Needless to say, real-time data can help prevent both scenarios, ensuring maximum occupancy on all levels, higher revenue, and better customer experience.

The Solution: Smart Wireless Parking Sensors

So how do we acquire this accurate, real-time occupancy data from the top floor? Wireless vehicle detection sensors, originally designed for on-street parking and outdoor lots, are the answer! In fact, they work for any parking spot – indoor, outdoor, rooftop or basement.

Harnessing the latest advances in IoT radio technologies like LoRaWAN and Bluetooth 5.0, these parking sensors are really smart. Why? One solution with 10-year battery life fits all types spaces and does not require any wiring, costly ceiling conduit or pole mount infrastructure.

If that’s not smart enough, how about using the same sensor in car counting mode for entry or exit lanes of a garage? It offers accuracy that cameras, radars, and lidars can’t match. Pretty cool for a small puck, right?

Maximizing the ROI of Parking Guidance System

The selection of the optimal PGS system depends on a few factors but the most important metrics are definitely your garage average and peak monthly utilization.

We published a detailed PGS Selection Guide to help you decide the best system for your parking facility. But naturally, the primary goal of implementing PGS (or any new technology) is to enhance asset efficiency.

To the improve the garage efficiency and utilization, a modern PGS solution needs to effectively share accurate parking availability data through multiple channels:

  1. Digital Message Signs (DMS) – at the entry and inside (large or complex facilities)
  2. Customer’s web site (APIs, widgets)
  3. Parking apps and platforms: Parkopedia, SpotHero, etc.

Besides real-time data sharing, historic data analysis can inform additional initiatives to maximize revenue. Managers can run different scenarios on occupancy vs. pricing and plan for peak hours, special events pricing, or promotional lower pricing in off-peak hours.

The variable pricing in general is one of the key mechanisms of revenue optimisation. Besides time domain, you can also look into a spatial one. Just like cinema or event ticket price varies with the view, parking rate can increase with the convenience or location of the spot.

As discussed, the rooftop spaces are less preferable than lower floors, so offering a slightly lower price can improve the flow, overall utilization and revenue. Such pricing model supported by data from vehicle sensors at the rooftop can help customers to take informed decisions and choose based on price and level of convenience trade-off.


In conclusion, implementing a modern Parking Guidance System (PGS) with accurate rooftop data within your parking facility is not merely about innovation for its own sake. It is a strategic step towards enhancing asset efficiency. Through real-time data sharing and informed variable pricing, PGS offers an opportunity to increase revenue and optimize usage. So, whether it’s about directing drivers toward underused rooftop spaces or facilitating easier decision-making for customers based on price-convenience trade-offs, PGS at rooftop plays a critical role. As the landscape of parking facilities evolves, it is this blend of technology and strategic planning that will ensure parking spaces are not just concrete structures, but smart structures contributing to a smarter and more convenient world.

Next Steps

Choosing the right PGS for a specific project is not a simple task. Do you choose a counting system or per-space, do you go with wired sonic sensors, cameras or wireless ground sensors, what are the relative hardware, installation and maintenance costs?

Drawing on our extensive hands-on experience across diverse parking projects, we’ve endeavored to offer an impartial and technical perspective on many of these questions in our PGS White Paper. This valuable resource is available for free online reading or download as a PDF for future reference.

If you are thinking that Nwave wireless PGS may be a good fit but still have questions, you may find our FAQ section to be a helpful resource. You may also want to reach out to us for a free consultation – it is our commitment to you to stay objective when it comes to pros and cons of different systems.