The Promise and Reality of 'Trackless Trams' in Public Transit

Urban planners have spent decades searching for the "Goldilocks" solution to public transit: a system with the high capacity and smooth ride of a light rail train, but the low cost and flexibility of a city bus.[3]

In recent years, a new contender has emerged from China, promising exactly that. Known officially as Autonomous Rapid Transit (ART), but more commonly dubbed the "trackless tram," the technology has captured the attention of municipal governments from Australia to the Middle East.[1]

Developed by the Chinese state-owned manufacturer CRRC, the trackless tram is essentially a crossover vehicle. It looks and feels like a sleek, multi-carriage modern train, but it runs on rubber tires rather than steel tracks.[1][2]

The core innovation lies in its guidance system. Instead of following physical rails embedded in the street, the ART uses a combination of optical sensors, LiDAR (Light Detection and Ranging), radar, and GPS to follow a "virtual track" of painted lines on the roadway.[1]

This optical guidance allows the vehicle to navigate tight urban corridors with centimeter-level precision. To ensure passenger comfort, the vehicles utilize stabilization and multi-axle steering technology adapted from high-speed rail, eliminating the jerky movements and sway typically associated with standard articulated buses.[1][2]

Power is delivered entirely through onboard batteries. Rather than relying on unsightly overhead wires or continuous electrified rails, the tram receives a rapid booster charge at dedicated station stops while passengers board and alight.[1]

For proponents, the primary appeal of the trackless tram is economic. Laying steel tracks for traditional Light Rail Transit (LRT) is notoriously expensive and disruptive, often requiring cities to dig up streets and relocate underground utilities.[2]

By eliminating the need for physical rails, advocates estimate that trackless trams can be deployed for a fraction of the cost. Some feasibility studies have suggested ART could be installed for as little as $10 million to $15 million per kilometer, compared to the $30 million to $130 million per kilometer often required for light rail.[2]

Furthermore, because the system is essentially a "kit of parts" that doesn't require heavy civil engineering, a new route can theoretically be launched in a matter of weeks rather than the years it takes to construct a traditional tramway.[2]

However, as the technology has moved from concept to real-world testing, a chorus of skepticism has emerged from transport engineers and urban scholars. Critics argue that the "trackless tram" branding is a clever marketing exercise for what is ultimately just a very long, technologically advanced bus.

The most significant hidden cost of the ART system is its weight. A fully loaded, three-carriage trackless tram can weigh up to 51 tonnes—roughly twice the legal limit for standard articulated buses.

Because this massive weight is concentrated on rubber tires following the exact same path on every trip, the vehicles can quickly degrade standard asphalt. Transit authorities have found that deploying ART often requires digging up the route anyway to install heavily reinforced concrete foundations, severely eating into the promised cost savings.

The "autonomous" label has also faced real-world friction. While the vehicles feature advanced driver-assistance systems, they still require human operators in most current deployments to handle complex urban traffic.

In a high-profile setback, Indonesia's new capital city, Nusantara, ordered an ART vehicle for testing in late 2024. After a brief trial period, officials returned the unit to China in early 2025, citing the system's inability to operate fully autonomously without manual intervention.

Other planned networks have also stalled. In Malaysia, the city of Putrajaya recently abandoned its ART proposal due to escalating implementation costs, though the state of Sarawak is still pushing forward with a hydrogen-powered variant slated for passenger service in late 2025.[1]

Despite the growing pains, transit experts acknowledge that the technology still holds value if cities understand what they are buying. It may not be a magical, zero-cost replacement for light rail, but it represents a significant upgrade over traditional Bus Rapid Transit (BRT).

Ultimately, the success of trackless trams will depend less on their futuristic branding and more on how cities integrate them. If paired with dedicated right-of-ways and high-density transit-oriented development, these rubber-tired hybrids could still play a vital role in decarbonizing the middle suburbs.[1]