How Trackless Trams Are Bridging the Gap Between Buses and Light Rail

Cities worldwide face a persistent transit dilemma: buses are cheap but often unpopular and slow, while light rail and subways are highly efficient but prohibitively expensive. In the United States, only a tiny fraction of commuters use mass rapid transit, largely because building a new subway line can cost billions of dollars and take decades. To bridge this gap, urban planners are increasingly looking toward a "mid-tier" solution that promises the best of both worlds. Enter the trackless tram, a hybrid technology designed to deliver the capacity and smooth ride of a train without the staggering infrastructure costs.[4][7]

Formally known as Autonomous Rapid Transit (ART), the trackless tram is essentially a multi-articulated electric bus that mimics the behavior of a light rail vehicle. Instead of running on steel tracks embedded in the street, ART vehicles run on rubber tires and follow painted lines on the road using a sophisticated array of optical sensors, lidar, and GPS. The technology was first unveiled in 2017 by CRRC, a major Chinese state-owned rolling stock manufacturer, and entered commercial service in the city of Zhuzhou the following year.[1][2][7]

The primary appeal of the trackless tram lies in its dramatic cost savings. Traditional light rail transit (LRT) requires tearing up city streets to lay steel tracks and install overhead electrical wires, a disruptive process that can cost anywhere from $50 million to over $130 million per kilometer. In contrast, proponents estimate that a trackless tram system can be installed for as little as $10 million per kilometer. Because the vehicles operate on existing roadways and use roof-mounted batteries that fast-charge at stations, cities can bypass years of agonizing construction.[2][3][4]

Beyond the balance sheet, ART aims to solve the comfort issues that plague traditional bus networks. CRRC adapted stabilization technology originally developed for high-speed rail to control the sway and swerve of the rubber-tired vehicles. Active suspension systems and multi-axle steering allow the long, multi-carriage trams to make tight turns along narrow urban corridors while providing a ride quality that feels distinctly like a train. A standard three-carriage ART vehicle stretches over 30 meters long, can travel at speeds up to 70 kilometers per hour, and is designed to carry up to 300 passengers.[1][2][3][4]

This combination of low cost and high quality has made trackless trams a focal point for urban regeneration strategies. Transit-oriented development (TOD) relies on the permanence of a transit line to attract private investment; developers are historically hesitant to build dense housing or retail around a bus route because a bus line can be moved overnight. Trackless trams, with their dedicated lanes and substantial station infrastructure, project the same permanence as a light rail, theoretically unlocking the same economic uplift for surrounding neighborhoods.[3][4][7]

The technology's promise has sparked global interest far beyond China. Trackless tram projects and feasibility studies have been launched in cities across Australia, the United Arab Emirates, Malaysia, and Pakistan. In Perth, Australia, local governments have aggressively studied the technology as a way to connect suburbs to the broader rail network without bankrupting municipal budgets.[1][3][4]

However, as the technology moves from controlled demonstrations to global deployment, a vocal contingent of transit skeptics has emerged. Critics argue that the term "trackless tram" is a marketing masterclass designed to obscure a simple reality: it is, fundamentally, a very long bus. By rebranding an optically guided bus as a "tram," manufacturers have successfully bypassed the stigma associated with bus travel, but skeptics warn that cities may be buying into a "gadgetbahn"—a proprietary, over-engineered solution to a problem that standard Bus Rapid Transit (BRT) already solves.[1][6]

The most significant hidden cost of the trackless tram lies in the very roads it drives on. A fully loaded three-carriage ART vehicle weighs approximately 51 tonnes. Because the optical guidance system forces the vehicle's rubber tires to travel over the exact same millimeter of asphalt on every single trip, the concentrated weight can cause severe rutting and erosion of standard roadways.[3][6][7]

This phenomenon is not entirely unprecedented. Older guided bus systems in Europe experienced similar roadway degradation, forcing municipalities to undertake expensive repairs. To prevent trackless trams from destroying city streets, transit authorities often must excavate the route and install heavily reinforced concrete roadbeds. Once the cost of this specialized road reconstruction is factored in, the financial advantage over traditional light rail begins to narrow significantly.[6][7]

The "autonomous" branding of the ART system has also faced real-world friction. While the vehicles are equipped with advanced sensors and can technically follow a painted line without steering input, they still require human operators for safety and complex traffic navigation. In 2024, Indonesia tested an ART system in its future capital city, Nusantara, but ultimately halted the project and returned the vehicles to China after determining they could not operate with the promised level of autonomy.[1][6]

Capacity claims have also been scrutinized. While manufacturers advertise that a three-carriage vehicle can hold over 300 passengers, transit authorities in countries like New Zealand have pointed out that this figure assumes a density of eight people per square meter—a crowding standard typical of a Chinese rush hour but rarely accepted in Western transit systems. When recalculated using a more comfortable standard of four passengers per square meter, the capacity drops closer to 170, which is only marginally higher than a standard articulated bus.[6]

Despite these hurdles, cities are finding creative ways to adapt the technology to their specific needs. In Malaysia, the state of Johor initially planned a ground-level ART system to alleviate severe traffic bottlenecks. However, after traffic impact assessments revealed that dedicating existing road lanes to the trams would only worsen street-level congestion, the government pivoted.[5]

In May 2026, the Malaysian federal government approved a restructured Elevated Autonomous Rapid Transit (E-ART) system for Johor. By placing the rubber-tired trackless trams on a dedicated elevated viaduct, the city aims to achieve the grade-separated efficiency of a monorail or subway, but at a lower cost and with lighter infrastructure requirements than a traditional heavy rail viaduct.[5]

The evolution of the trackless tram highlights the broader growing pains of mid-tier transit. As cities desperately seek alternatives to the binary choice between cheap buses and exorbitant subways, hybrid technologies will inevitably face intense scrutiny. Whether ART is viewed as a revolutionary leap in urban mobility or simply a brilliantly marketed bus, it has undeniably forced urban planners to rethink what is possible in the space between the sidewalk and the steel rail.[2][4][7]