1. Transport
December 23, 2020

Trackless trams may be the best alternative to light rail

Combining the best of high-speed trains and autonomous-vehicle tech, they are emerging as a less expensive, more sustainable option.

By lisa chamberlain

An emerging alternative to traditional light rail, known in the English-speaking world as trackless trams, has been under development for a mere five years by the Chinese high-speed-rail authority – and yet is already operating in three cities there. Trackless-tram projects are deep in the planning phase in Qatar for the 2022 FIFA World Cup as well as several places in Australia, including Melbourne, Western Sydney, Townsville and Perth. It’s also being studied in Pottstown, just outside of Philadelphia in the US.

a trackless tram, an alternative to light rail
Above, an autonomous rail transit system launched in 2018 in Zhuzhou, China. (Photo courtesy of CRRC)

The trackless tram, or autonomous rail transit (ART) as it is known in China, combines the best of high-speed rail and autonomous-vehicle (AV) technology with on-street mass transit to achieve a flexible, carbon-neutral and cost-effective urban connector. It is sold as a kit of parts – three cars plus a station – that can be installed about as fast as a city’s permitting process would allow, according to its proponents.

Planners from Perth to New York City say it is the best possible use of AV tech in the urban context and a critical advancement in the era of climate change and our increasingly crisis-prone world. Others are taking a wait-and-see approach. But as with all innovations, whether trackless trams succeed on a mass scale depends as much on political and business interests as technology and design. “When it’s up and running in Perth, we’ll see,” says Sam Schwartz, a former traffic commissioner in New York City and the founder of an eponymous engineering company. “If it’s successful there, there will be slow exponential growth and then faster as it becomes more widespread. There’s a whole revolution of information technology that the transit industry has been incredibly slow to embrace.”

How trackless trams functions

Peter Newman, a professor of sustainability at Curtin University in Perth, is a staunch advocate for trackless trams. He was one of the first non-Chinese transit experts to visit the factory in Zhuzhou, China, where such streetcars continue to be developed. After 40 years of rail advocacy, Newman had to acknowledge that light rail is not always the best answer to urban transportation. This became clear to him when Sydney went way over budget installing light rail in its downtown core, disrupting the business district for years. But he doesn’t believe buses are the answer, either.

“Buses can’t compete with rail,” Newman says. “They don’t get people out of cars. So I started looking around for alternatives to light rail and came upon an article about this new streetcar being developed in China.” He went to Zhuzhou in August of 2018 when the tram was still being tested.

“I was convinced with one ride,” he says. “Doing 70km an hour, it rode like a train. The ride quality convinced me this is the future of transit. All of the problems with buses are gone: the jerkiness, the slowness, the vibration.”

Upon his return from China, Newman co-authored a study and wrote a series of articles and papers. One paper he co-wrote, published in the Journal of Transportation Technologies in 2019, quantified the significant cost savings of trackless trams compared with light rail.

In Sydney, for example, laying 20km of track through the oldest part of the city took five years and cost about $130m per kilometre. By contrast, trackless streetcars can be installed for as little as $10m per kilometre. That’s probably a lowball estimate, but it is orders of magnitude less than light rail.

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The largest cost savings come from not having to lay rail in the roadbed, especially in dense urban environments. Rather than running on tracks embedded in the street, the trams have rubber tyres that follow painted lines with centimetre accuracy by using laser technology and GPS positioning. Of course, this means the streetcars work best on rights of way that need regular maintenance, but so do all mass transit projects, including bus rapid transit (BRT). While trackless trams are more expensive than BRT, proponents point out that they move more people and have a much smoother ride due to the stabilising technology adopted from high-speed rail. What’s more, most BRT projects are not electrified.

The adaptation of high-speed-rail stabilising technology isn’t just about comfort but to control the sway and swerve, enabling the skinny streetcars to make tight turns and travel along narrow corridors. The use of advanced batteries mounted on the roof eliminates the need for ungainly overhead wires. Trams recharge at the station within 30 seconds as passengers load and unload (with longer charges at the end of the line and overnight). And while the streetcars utilise AV technology, there is a driver on board with the ability to modify the route or stop the tram in an emergency, mitigating the dangers posed by driverless cars zipping unpredictably around dense urban neighbourhoods.

Can trackless trams work outside China?

Perth will be the first place outside China to implement the trams. With a $2m grant from the government, the first phase of implementation, designed to connect the central business district with a suburban neighbourhood, will be underway in a matter of months. For transit experts and urban planners outside China who have not studied this emerging technology closely, what happens in Perth is the first real test.

Schwartz believes autonomous rail transit is the best application of AV technology in the urban context he’s seen thus far. He maintains that driverless technology applied to individual cars is not ready for big cities – and may never be. But he is also cautious about how far along trackless-tram tech really is.

John Shapiro agrees. A professor of planning at the Pratt Institute School of Architecture in Brooklyn, New York, who also consults on large-scale redevelopment projects, he has recently become familiar with the trackless tram. And while he can envision many applications for it, he is not convinced it is ideally suited to a dense urban environment, especially in a place like New York City where the installation of a bike lane can ignite street fights and lawsuits. That’s not to say it wouldn’t work in the urban context, but technology is not the limiting factor – competition for street space is.

Perhaps even more important for autonomous rail transit, says Shapiro, is whether it is embraced by developers. He agrees with Newman that buses are viewed as transportation for the working class, and if the tram is perceived as just a glorified bus, it will not succeed as a tool for transit-oriented development.

“It has some of the romance of fixed rail, and real estate interests may be willing to back it as a compromise, but they may not because the advantage of rail is – even if ridership is low – it’s not going to go away,” Shapiro says. “The flexibility of trackless tram is critical in a time of climate crisis, and it would seem to be a good alternative where light rail is being considered. The cost and timeline of light rail, especially in areas affected by flooding and climate change crises, is not really sustainable.”

The question of whether real estate interests are willing to make this compromise has been playing out in Brooklyn. A proposed waterfront light-rail project known as BQX – the Brooklyn Queens Connector – was enthusiastically backed by the Brooklyn-based real estate company Two Trees, led by billionaire developer Jed Welentas. The escalating price tag of BQX, however, has all but killed it (an estimated $2.7bn for 11 miles of light rail). Welentas declined to comment on the trackless tram, but his organisation has recently reached out to Newman to explore it as an alternative option.

[Read more: What is a 15-minute city?]

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