The Southwest Ohio Regional Transit Authority is the public transport agency serving Cincinnati.

The Southwest Ohio Regional Transit Authority is the public transport agency serving Cincinnati.

Photo: SORTA

There is a certain inevitability to the rise of Real-time Location Systems (RTLS).

While they have existed in certain forms since the 1970s, they really started to take off in 2017 as IoT devices began to proliferate in the industrial sector. Now, due to the pressures facing many mass transit systems, and the increasing complexity of those systems, many transport hubs have begun to see the benefits of RTLS and the Industry 4.0 revolution.

But how do these systems work and what are the exact benefits?

RTLS, A Quick Explanation

Real-time Location Systems are used to track the precise locations of any vital assets within a working environment. By tagging and tracking assets, including vehicles, machinery, and even people, one can create a digital twin of that environment, gaining better oversight of all activities. Using AI and traditional analysis methods, one can prevent system bottlenecks, locate lost items (i.e., vehicles), and pursue “optimal efficiency.” 

Due to the system’s ability to report in real-time, assess thousands of data points at any given time, and visualize its data in a simplified fashion, RTLS can optimize complex transit hub activities in a way that would otherwise be impossible. The days of physically having to walk through a site, and checking vehicles are parked correctly, are gone. There are no more human errors due to clipboard and paper checks. Drivers can be alerted to changes in their schedules automatically. And, it is instant. 

How RTLS Works

To use an RTLS for transit yard management, one usually requires the help of a company specialized in installing RTLS systems — which will usually have access to the appropriate hardware and software. Usually, the RTLS company will begin by scanning the site(s) in question and creating a virtual map of the space. They will then install sensors in strategic locations around the site. Once the sensors are set up correctly, the vital assets can be tagged with a variety of tags, depending on the types of assets and whether they operate outdoors or indoors. 

View of a UWB sensor in a bus depot.

View of a UWB sensor in a bus depot.

Photo: Ubisense

The interaction between the tags and sensors will allow specialized software (either hosted on-site or in the cloud) to process and visualize real-time location data for the tagged assets. This software can often be customized to the client’s needs, displaying exactly what they need to see and driving specific insights and alerts.

View of a simple transit hub interface.

View of a simple transit hub interface.

Photo: Ubisense

What RTLS is Doing for Transit Hubs 

RTLS has already embedded itself in many different transit hubs around the world, particularly in coach and bus depots. By tracking the real-time location of vehicles across indoor and outdoor spaces, one can eliminate wasted search time and automate many time-consuming processes.

The barriers that control entry and exit to a location can be automated, opening when correctly tagged vehicles or personnel come within a defined proximity. Drivers can then be guided to parking spaces, chosen by the tailored software to place them in the best possible position for maintenance and dispatch tasks, reducing the need for unnecessary shuffling. Vehicles in need of maintenance can be linked to service schedules and tracked accordingly, their icons changing color as they move through the maintenance process. When ready, they can then be dispatched with the correctly assigned routes. 

These are just some of the ways an RTLS can be utilized, and individual transit hubs will find further uses for RTLS. For example, many will use their RTLS to help with worker safety hazards, even having them send social distancing and contact tracing alerts. You can see some recent case studies of transit businesses with RTLS systems here: Transit Yard Management.

Choosing an RTLS system 

There are a great variety of RTLS businesses in operation, and they all use different technologies and are suited to different environments. While scanning barcodes and passive RFID tags can technically constitute a basic RTLS system, some of the more common RTLS technologies are listed below:


UWB is one of the newer but more versatile RTLS technologies. UWB (Ultra-wideband) uses specialized radio signals that can provide centimeter-level accuracy and don’t suffer from interference, like many other positioning technologies. Their accuracy and reliability have made them the technology of choice for many transit hubs, but not all UWB RTLS systems are of the same quality. It is crucial to ensure that a UWB system is truly accurate and can also be used effectively in any outdoor environment. Some companies can offer UWB-integrated RTK GPS to provide seamless tracking between indoor and outdoor environments. 


Bluetooth Low Energy is a common technology nowadays. It is the same Bluetooth technology one uses in their mobile phone or smartwatch, and that is both beneficial and problematic. BLE RTLS systems can be simpler and more cost-effective to set up, and they can integrate many Bluetooth-enabled devices, but they will also suffer Bluetooth’s limitations. The signals are far more inaccurate than UWB and they are prone to interference. They also don’t have the same range. If looking into BLE systems, it is best to ensure that simple system functionality is all that is required.


GPS has traditionally been used to generate accurate readings to within a few meters, but this often isn’t enough for accurate parking and security measurements. However, RTK GPS can offer much more accurate readings and can be excellent for tracking vehicles over large outdoor areas. While RTK GPS will still not provide accurate readings within buildings and covered parking areas, it can complement other RTLS systems looking for both indoor and outdoor tracking.

From the above, you can see that RTLS is a varied and often complex technology with interesting implications for transit hub efficiency. As the technology continues to develop, and more transit companies discover the potential cost savings RTLS creates, these systems will only continue to proliferate. 

Steven Manifold is CMO at Ubisense.