Dubai’s announcement that it plans to create a high-tech network of trackless trams strengthens the city's public transport offering but may not on its own reduce congestion, analysts have said.
Plans to develop the network at eight locations were revealed this week by Sheikh Hamdan bin Mohammed, Crown Prince of Dubai, Deputy Prime Minister and Minister of Defence.
Dubai’s Roads and Transport Authority has been instructed to develop the plans for a network of self-driving trams that will use cameras to follow painted lines on dedicated lanes. Rather than being powered by overhead lines, the three-carriage trams will have batteries that allow them to travel as far as 100km.
Trackless trams offer many of the benefits of trams that run on rails, but at lower cost, suggested Marcus Enoch, professor of transport strategy at Loughborough University in the UK.
"There's a lot of technologies around now. Instead of having to put in a proper steel-rail tram system, you get the benefits of a modern-looking public transport system that wealthier people will be willing to use," he said.
"If you can do that by … the vehicles having rubber tyres like on a bus, rather than a steel rail, it's much, much cheaper to build."
It is much faster to develop a trackless tram system than a standard tram, as there is unlikely to be the same need to dig up road or other areas to lay the rails.
This requirement, he said, had complicated the building of some rail-based tram systems because of the risk of damaging utilities infrastructure beneath the surface. Such systems can, he said, take 10 years or more to implement.
A straightforward system
The proposed Dubai system, by relying on batteries rather than on overhead lines, may be particularly straightforward to implement. Another potential upside may be greater flexibility on where the trams can run.
"I don't know how long it takes them to source the vehicles and the equipment and the depots – a minimum of a year," Prof Enoch said.
The Dubai system will involve three-carriage trams with a top speed of 70kph and operational speeds between 25kph and 60kph. Much of the development work for trackless trams has been carried out by firms in China.
Prof Enoch said passenger comfort may improve because the vehicles run on rubber tyres rather than steel rails, with better braking and acceleration. Also, because they are precisely guided by technology, trackless trams can operate in relatively narrow lanes, with minimal extra space required on either side, he added.
But standard rail-based trams may have more passenger appeal in some respects.
"I think your standard tram is still probably your quality offer," he said. "There's a certain solidity about traditional trams. They've been there for 150 years. They're part of the urban fabric.
"In image, trackless trams are still a bit arriviste. The fact you have rails and overhead lines reassures passengers it will turn up."
With buses in particular, he said some passengers may be more concerned about reliability.
Related forms of transport, such as guided buses, have been around since the 1970s, Prof Enoch said, and there is now "a massive range of these technologies".
However, he added that until now "they have not taken off" in a widespread way, in part because buses may struggle to attract people who have the choice to travel by car.
Prof Enoch said the transport sector was "probably at a tipping point" in terms of the technology around trackless trams and related forms of transport.
"Until now it's just not been trusted," he said. "Big public transport agencies are thinking, 'Can we depend on it?'"
What Prof Enoch described as "a big showcase" for the technology, such as a major introduction in the UAE, could help to speed wider adoption.
'A narrow niche'
Peter Schwinger, an independent transport consultant in Belgium who has worked in the UAE, said that trackless trams offered advantages over other forms of public transport "only in a relatively narrow niche".
This niche, he said, sat between rail-based mass transit (which is suitable when there is higher demand) and buses on a dedicated lane (which works better for lower-demand routes). Mr Schwinger said the advantage of trackless trams only applied on new corridors designed exclusively for them, which comes at a higher cost.
"As soon as the tram operates outside these corridors, all bus bays would have to be converted into kerbside stops," he said.
Such kerbside stops are, he said, "a common infrastructure feature in Europe" but rarely found in Gulf cities.
This issue was seen, he said, with the tram-like Autonomous Rapid Transit, an electric bus service that connects Reem Mall with Rixos Marina Abu Dhabi. The ART vehicles stop at bus stops but are unable to pull directly into them.
Dr Alexandra Gomes, a London School of Economics research fellow who has analysed transport in the region, said improvements in public transport in Gulf cities, especially mass transit with dedicated lanes, were "generally beneficial".
"However, if the expansion of public transport – even with autonomous and eco-friendly systems – also includes an increase in road capacity without better integration of the transport network, the expected reduction in cars on the road may not occur," she said.
"People may be reluctant to switch to public transport if it does not offer significant advantages in travel time or flexibility of movement."
Reducing traffic congestion
She said "a co-ordinated, compact and connected approach" could help Dubai to reduce car usage, which means increasing urban density, promoting mixed land use and investing in "a well-integrated transport network with effective management".
"Investment in walkability and active mobility modes, such as cycling, should complement public transport investments, for a more sustainable and flexible approach," she said.
"Additionally, it is crucial to consider which areas are being served by these transport lines. Are they connecting people to key destinations, such as workplaces, education centres, and essential services?
"The alignment of these new transit routes with residential densities, areas of poor transport accessibility, and key destination points can significantly enhance the interest and impact of this investment."
