The Future of Rail Safety: TTC’s Grade Crossing Testbed

Located in Pueblo, Colo., the Transportation Technology Center (TTC) has been a vital asset for rail safety research. Now, it’s undergoing a transformation into a modern, surface transportation test facility, with new capabilities designed to address critical safety challenges such as grade crossings. 

Grade crossings—where roads meet train tracks—have always been high-risk areas. They involve complex interactions between trains, cars, trucks, pedestrians and cyclists. According to the Federal Railroad Administration (FRA), about 2,252 grade crossing incidents occurred across the U.S. in 2024, leading to nearly 263 deaths and more than 751 injuries.1 These events not only cause human tragedy, but also major disruptions to transportation and the economy. Remaining challenges still exist due to the complexity of these crossings, which continue to create serious safety risks. 

Advancing technologies bring an opportunity to decrease grade crossing fatalities and injuries by addressing remaining challenges. Human factors-related challenges, such as distraction, impatience and misjudging signals, remain a leading cause of accidents at crossings. This highlights the urgent need for better technology, smarter design and a clearer understanding of how people behave at crossings. 

To address this, the FRA and ENSCO worked together with the support of an advisory group to explore the development of a dedicated grade crossing testbed (GX testbed) at the TTC, paving the way for groundbreaking research and development. 

An innovative testing ground 

The GX testbed offers a unique, controlled setting for transportation safety research. Its purpose is to create a flexible and realistic environment where advanced safety solutions can be thoroughly tested. Unlike the unpredictability of public roads, the testbed allows researchers to safely study a wide range of scenarios without risk to the public. 

Today’s transportation systems are increasingly connected. Modern networks require clear communication between cars, trucks, buses, trains and pedestrians. TTC’s existing cellular and fiber optic infrastructure supports these technologies, making it uniquely equipped to facilitate real-time communication systems like Cellular Vehicle-to-Everything (C-V2X). With the rise of autonomous vehicles (AVs) and smart infrastructure, the GX testbed at TTC is essential to safely test and refine these systems before they’re put into real-world use. 

Collaborative vision: Stakeholders shaping safety 

Collaboration is key to the GX testbed’s success. An advisory group, including representatives from U.S. Department of Transportation agencies, universities and industry partners, helped shape the vision. Their input was vital in defining the features needed for a modern, effective testing environment. 

Stakeholders emphasized the importance of a flexible design that can recreate different real-world scenarios—busy city intersections, rural crossings, areas with low visibility and more. They also identified technologies like 5G connectivity, radar, Light Detection and Ranging, artificial intelligence -powered cameras and C-V2X communication as essential tools. To better understand human behavior, the group also recommended equipment like eye-tracking and biometric sensors to study how drivers, cyclists and pedestrians react in different situations. 

Human factors and behavioral research capabilities 

Understanding how people behave is a critical part of transportation safety. The GX testbed is envisioned to include special tools to study human factors like eye-tracking systems, biometric sensors that monitor stress and reaction time and advanced simulation software. These tools will help researchers understand how people respond to warnings, signage and different crossing configurations. The results can directly lead to improved crossing designs, smarter warning systems and better public safety programs. 

Crossing into the future 

A feasibility study looked at existing grade crossings and proposed new ones, ultimately identifying three key areas to study at TTC: Post 85, Post 100 and the new train dynamics track (TDT) grade crossing. 

• Post 85 is an active, multi-track grade crossing located at transit and freight test tracks at the TTC. Thanks to its strong infrastructure, it only needs updates to communication and sensor systems. It’s ideal for testing complex scenarios involving trains, buses and road vehicles. However, it has limited approach speeds and lacks dedicated infrastructure for pedestrians and cyclists, limiting its use for wider multimodal research. 
• Post 100 is another active grade crossing that offers a balanced setup. It includes a rural track with speeds up to 165 mph, overhead electric wires (catenary), existing fiber optics and traditional crossing barriers. Planned upgrades include new sensors, a redesigned road layout with multiple lanes and better pedestrian and cyclist access. It offers more flexibility than Post 85 but still faces some limits due to the existing infrastructure like the catenary poles.
• TDT new grade crossing is a newly proposed design meant to be the centerpiece of TTC’s multimodal testing as shown in Figure 2. Located on a curved rail section, it allows for diverse vehicle approaches and speed testing. The modern road design will include pedestrian and cyclist paths, multiple lanes and a side road. It’s also expected to have lighting systems, mock buildings and tools to simulate different weather conditions. The open surrounding area supports future expansion, making it ideal for new and evolving test scenarios. 

The GX testbed will go far beyond traditional rail crossings. Intersections at the testbed will be designed with modular components such as signage, signal types, road layouts and surface materials that can be adjusted to simulate a variety of urban and rural environments. Systems for fog, rain, snow and changing light will also enable realistic weather testing. Advanced sensors capture detailed data, providing essential insights into both technological and behavioral responses. By using different combinations of existing crossing types at the TTC, researchers can simulate a wide range of scenarios to study how people and systems respond to varying conditions. 

Multimodal integration 

Building on its multimodal capabilities, the GX testbed supports rigorous testing across a wide range of transportation systems, including AVs, intelligent transportation networks, commercial fleets and pedestrian safety technologies, all within a controlled environment.  

This unique capability positions the GX testbed to attract diverse stakeholders—from automotive companies testing self-driving technologies to technology companies developing next-generation communication solutions.  

TTC’s unique position and legacy 

TTC is uniquely qualified to host the GX testbed because it is the only facility in North America and one of the few globally capable of full-scale, high-speed testing of rail vehicles, including speeds up to 165 mph. Its unmatched capacity includes controlled crash testing, track infrastructure experimentation and systems validation across a secure, expansive campus. Over decades, TTC has pioneered advancements such as Positive Train Control (PTC), heavy axle load research and crashworthiness evaluations, making it a proven leader in transportation safety and innovation.  

Today, TTC is uniquely positioned to lead global multimodal transportation safety innovations, including  technologies such as  C-V2X, which enhances road safety, traffic efficiency and mobility, particularly where road and rail vehicles intersect. TTC’s existing cellular infrastructure enables real-time communication between vehicles, infrastructure and road users, making it an ideal environment to test and refine these systems. Advancing C-V2X applications at grade crossings could significantly improve safety while reducing long-term infrastructure costs.  

Data from TTC’s GX testbed will inform transportation policy and regulatory frameworks, speeding up the adoption of effective safety technologies and practices nationwide, significantly shortening the gap between innovation and implementation. 

The GX testbed will also serve as an educational resource, offering training opportunities for rail and transit professionals, students in engineering, urban planning and transportation fields. Community engagement programs will emphasize public responsibility in transportation safety. 

A phased approach for lasting success 

The GX testbed will be developed in phases. Initial steps include implementing advanced sensing technologies and communications infrastructure. Later phases will integrate cutting-edge AV testing capabilities and gradually develop more complex testing scenarios. Each phase builds incrementally, ensuring sustainable growth and allowing continual adaptation to emerging transportation safety challenges. An example is the proposed enhancement to the Post 100 Grade Crossing as shown in Figure 3.  

Looking ahead 

The GX testbed is more than just a facility; it represents a long-term commitment to safer communities, innovative transportation solutions and sustainable development. Through continued collaboration among government agencies, academia and private sector partners, the TTC GX testbed will help lead to advancements in transportation safety for decades to come.