Recent innovations in transport technology are now providing mobility that is cheaper, autonomous, electric, and with improved ride quality. While much of the world’s attention has been on how this can be applied to cars, there have been rapid adoption of these and other technologies in High Speed Rail and Metro Rail systems that run between and across cities. This paper shows how such innovations have now been applied to create the next generation of urban transit system called a Trackless Tram. Trackless Trams are effectively the same as traditional light rail except they run on rubber tyres avoiding disruption from construction for Light Rail, but they retain the electric propulsion (with batteries) and have high ride quality due to rail-type bogies, stabilization technologies and precision tracking from the autonomous optical guidance systems—with infrastructure costs reduced to as low as one tenth of a Light Rail system. As with Light Rail, a Trackless Tram System provides a rapid transit option that can harness the fixed route assurance necessary to unlock new land value appreciation that can be leveraged to contribute to construction and running costs whilst creating urban regeneration. The paper considers the niche for Trackless Trams in cities along with its potential for city shaping through the creation of urban re-development along corridors. The paper suggests that the adoption of Trackless Tram Systems is likely to grow rapidly as a genuine alternative to car and bus systems, supplementing and extending the niche occupied by Light Rail Transit (LRT). This appears to be feasible in any medium-sized or larger city, especially in emerging and developing economies, and case studies are outlined for Perth and Thimpu to illustrate its potential.
Cities around the world now have a range of new technologies related to transport to choose from, such as electric vehicles and charging infrastructure, driver-assist and self-driving vehicles, low-cost sensors, increasing travel data sources, Big Data analytics software, internet-of-things platforms, and even more recently, artificial intelligence, machine learning and distributed ledger technologies. Considering the innovation of autonomous vehicles, Kim [
On the other hand, the autonomous, electric and stabilization transit technologies developed for High Speed Rail (between cities, over 300 kph) and Metros or Suburban Rail (within cities, 80 - 150 kph) have developed the speed, capacity and ride quality that have led to spectacular increases in ridership [
The response in recent years has been the development of autonomous mass transit that can be implemented in car dependent cities to complement and extend the effective catchment of traditional heavy rail or metro-based commuter systems. This is the niche of LRT and BRT, however in order to provide effective solutions for the world’s growing cities the technology used must overcome the issues of street disruption and capital costs as well as keeping all the good qualities of an LRT or BRT. This has meant merging innovations from High Speed Rail such as autonomous operation, stabilisation and ride quality, with the best parts of a light rail and a bus, to create a new form of urban transit technology. This paper will examine such a technology, which has been called Autonomous-Rail Rapid Transit (ART) or what we are labelling a Trackless Tram System (TTS).
Both bus and light rail technologies have been developing in recent years. For example, there are now many manufacturers of electrically powered buses, and many cities which are adopting them, to reduce the air pollution, noise and vibration problems associated with conventional diesel buses. A number of guided bus systems have also been installed using a variety of guidance technologies, from mechanical (as in Adelaide’s “O-Bahn”) through to optical and magnetic systems. Recent light rail vehicles also now feature on-board batteries or super-capacitors enabling wire-free operation (with re-charging at stops), as well as regenerative braking (to save energy), 100% low floor access (improving customer convenience and accessibility) and improved steering technologies for improved ride quality.
China’s CRRC (now the world’s largest rolling stock manufacturer) has combined all of these advances into its new “Trackless Tram”. This is an articulated, high capacity “Tram” running on rubber tires but with an in-built guidance system offering autonomous optically-guided running and operation. It is battery powered (with recharging at stops or at the end of the trip), avoiding the necessity for overhead wires along the route. It is fully low-floor, but uses improved suspension systems providing high ride quality. It has low axle loads, minimizing the need for expensive guide way infrastructure. It can also operate on regular streets because of its tight turning radius and high hill-climbing ability.
Three of the authors of this paper were able to visit China in August 2018 and ride the Trackless Tram as well as receive detailed explanations about how it works and how the transit system is constructed and operated. The paper is therefore based on this transit technology though it is not excluding other manufacturers such as Alstom, Van Hool, Irizar, and others. The technology was first taken to scale in China in 2016 on a straight 3.6 km line with 4 stations. Based on findings from the study tour to Zhuzhou, China it is the intention of this paper to not only demonstrate that the Trackless Tram is a superior technology for many corridor connections in urban transit systems but to explore the notion that it is potentially the public transport catalyst that many city planners have been waiting for since the dominance of automobile dependence, as it can unlock urban regeneration. It is the conclusion of this paper that not only is this technology a potential game changer for cities struggling to attract investment in traditional light rail projects, if implemented through an entrepreneurial approach in collaboration with the private sector it stands to unlock significant urban re-development options.
It is important to realise that the Trackless Tram System lends itself to an entrepreneurial approach where secure private sector investment can be attracted to create new development around station precincts, referred to by Newman et al. [
1) It harnesses electric drive systems and on-board battery technology to avoid the need for overhead cabling or a fossil fuel engine, with recharge at either stations or end of run areas for longer periods;
2) It substitutes the steel wheels of a train with rubber tyres. This avoids the need for rails and reduces the associated disruption of local economies due to extensive period of construction works on roads and underground services for traditional light rail systems;
3) It provides stabilization technologies through train-type bogeys with low set axles and hydraulic systems designed to prevent sway and bounce; and
4) It adopts autonomous technology through optical guidance systems to provide a precise and smoother ride quality and precision entry to stations and ease of boarding and lighting at platforms by passengers.
Considering the system configuration, the Trackless Tram System uses a dedicated corridor to provide rapid transit services that is supported by fixed stations and a Control Centre, much like light rail or traffic management centres. This provides the benefits in terms of city-shaping provided by traditional light-rail systems. However, the technology provides the flexibility to enable Trackless Trams to be diverted around blockages or quickly recalled should the need arise, unlike an LRT.
A Trackless Tram uses rubber wheels that drive on the surface of the road which avoids the need for a substantive part of civil works associated with rail infrastructure. Rubber-tired transit vehicles are a well-established technology. For instance, Michelin patented a steel-belt rubber tire in 1946 which was introduced to regular service on the Paris Metro from 1956. Other cities have developed rubber-tired mass transit systems, including Taipei’s Wenhu Line which is an automated rubber-tired train service running on metal plate as part of an elevated track, as shown in
This switch in the design avoids the majority of excavation of the road surface to construct concrete foundations and lay rails, as shown in
Length | 31.6 m |
---|---|
Width | 2.65 m |
Weight (loaded) | 51 tonne (average 9 tonne per axle) |
Capacity | 250 - 300 people |
Max speed | 70 km/hr |
Gradient | 13% |
Turning Radius | 15 m |
Design Life | Over 30 years |
a smooth arrival at stations it may be appropriate to construct concrete pads, however the CRRC claim that its light construction means that it can be implemented very rapidly into most urban road systems without change and that after three years of trials there is no sign of road damage.
Implementation is therefore possible to do in a weekend (after all approvals have been gained of course) with modular stations that come as part of the cost of the Trackless Tram System. These contain the desired ticketing and gateway systems as well as recharging facilities for rapid (30 seconds) recharging at stations or longer recharging at the terminus of a route. Implementation can also be simply integrated into a Bus Depot for overnight storage and deep recharge and can use a normal main roads Control Centre to ensure it is running well. The guidance system software and technology to create the exact route can be installed well before the system needs to be running. The best way to enable a mass transit system in a street is to create a free-flowing space and this will require detailed planning but no more or less than with a BRT and probably less than an LRT.
The big difference in implementation of TTS compared with conventional light rail is that a TTS avoids excavation of or interference with buried services such as water mains, electricity cables, telecommunications lines, storm water and waste water systems that add substantially to the cost if disturbed. According to the manufacturer a Trackless Tram vehicle has a loaded weight of 9000 kg per axle, which is similar to a conventional bus or heavy vehicle but has significantly less pavement impact due to its double axle bogeys, special tyres and the IMU system which manages the sway which causes pavement rutting. Hence pavement construction should not need to be any different for Trackless Trams. There are reasons why the autonomous driving character will minimise road damage as it is not subject to the heavy momentum swings associated with sudden driver interventions. No rutting has been found in the first three years of operation of the Trackless Tram in China (
The Trackless Tram combines a number of autonomous vehicle guidance technologies to follow “virtual rails” along its corridor. The main elements of the guidance system are imaging recognition for optical guidance, satellite navigation, radar point scanning and inertia management. These systems are likely to be used for many autonomous vehicles, especially transit systems that operate in traffic as will be the case in most cities. The lines marked on the road provide optical guidance while also clearly identifying the path of the vehicle for pedestrians and other motorists. Additionally, a differential global positioning system (DGPS) uses fixed positions along the path of the vehicle to constantly update the relative location signals sent and received from satellites―increasing the location accuracy to the order of 10 - 15 cms from what can be up to 15 m with traditional GPS. Radar and light point scanning (Lidar) enhances the vehicle’s ability to recognize route signs, network characteristics and dynamic interferences
that may occur, fitting this data to the information sourced from the other guidance technologies to create an overall sense of the surrounding environment.
The high precision achieved through the combination of these technologies adds to the appeal of the Trackless Tram by significantly increasing ride quality, improving the safety of the network, and reducing the damage caused to the road surface [
The Trackless Tram is electric and is powered by on-board lithium ion phosphate batteries (with a 25-year lifespan) that are supplemented by regenerative braking. The form of battery used by CRRC can recharge faster than many other lithium ion batteries and perform better in cold conditions. The 600 kW-Hr on-board batteries can quick-charge at 10 kV platform-style overhead charging stations during normal operation, and do 10 minute recharging at the end of a line as well as a deep recharge overnight in a Bus Depot. The CRRC Corporation estimates that for their 3rd generation vehicle a 10-minute charge can provide enough energy for between 15 and 25 km of travel depending on the loading and the level of air-condition required; with the fourth generation Trackless Tram the battery is anticipated to extend this to 50 - 60 km. Given the imperative to shift away from fossil fuels, especially diesel causing health impacts in cities, the electrification of transit systems provides a way to harness renewable energy generation, especially during daylight hours when solar energy is generated. Along with these improvements an electric drive system offers better ride quality through smoother acceleration/deceleration and less vibrations compared with an internal combustion engine vehicle.
The cost of Trackless Trams can be substantially lower than that of light rail. For instance, in a report commissioned by the City of Parramatta in Sydney, Bodhi Alliance and EDAB Consulting [
Compounding this problem, records are often not able to pinpoint the exact location of services, and in some cases the record of their very existence may have been lost. This creates a major uncertainty in the cost of the infrastructure provision for urban rail-based systems. This uncertainty is a particular problem in older cities, where infrastructure may have been laid down many years ago. While light rail projects typically take years to build, the Trackless Tram can be installed much more quickly (assuming suitable quality roadways and stations being prefabricated for rapid onsite erection). This will reduce the level of disruption to businesses, residents or traffic flows associated with light rail construction, though space must still be found in the roadway.
The Oxford Dictionary defines “interoperability” in the context of computer systems as a characteristic of a system where the various components are able to work with one another and exchange information despite being of different form, and use the example “interoperability between devices made by different manufacturers” [
The following examples illustrate the fleet size and transit service possible from such a system:
1) Trackless Tram Corridors: Much like light rail systems, Trackless Tram Systems are well suited to corridors of 8 - 20 km that serve the inner areas of large cities with stations spaced in the order of 600 - 1200 m apart, serving 1.5 km around each station. For instance, a 20 km line with 25 stations and three autonomous shuttles per station (carrying up to 12 passengers) that provides a service every 20 minutes would be able to feed around 120 people per hour into the station and service up to 3,000 people per hour along the entire corridor.
2) Low Density Heavy Rail Corridors: Modern heavy rail lines are fast and have high capacity, carrying people along long corridors with stations around 3 to 4 km apart. A Heavy Rail transit line from the CBD extending out 30 km with 8 stops would need each station to be serviced by a larger fleet of autonomous shuttles than a Trackless Tram System. To provide a service every 5 minutes each station would have around 6 shuttle loops with 4 shuttles per loop to service a 2.5 km radius around the station (creating an urban corridor of 150 km2). This would require in the order of 192 shuttles for the entire line that would have the potential to deliver nearly 7000 people per hour to the system, in addition to those that walk or cycle, or use a conventional bus to reach their local station. Such lines could also be linked radially around cities by Trackless Tram corridors.
3) Medium Density Heavy Rail Corridors: For higher density corridors like traditional transit fabric from the early 20th century, stations would generally be closer together (traditionally 1.6 km apart) and would have higher capacity of around 20,000 - 40,000 passengers per track per hour. With stations spaced every 1.5 - 2 km, smaller catchments per station would allow higher frequency autonomous shuttles (providing a service every 3 minutes), with the capacity to deliver nearly 12,000 passengers per hour to the system. Again, such lines could also be linked radially around cities by Trackless Tram corridors.
4) City Wide Application: Considering a city in the order of 2 million people, and assuming a corridor transit network of 15 heavy rail lines and 20 trackless Tram (TTS) lines this would involve 200 heavy rail stations (each with an average of 20 shuttles) and 500 TTS stops (each with an average of 3 shuttles)―so a fleet of 5500 shuttles would be required to service the entire city. Assuming each shuttle delivers 20 passengers per hour to a station the system could deliver as
many as 110,000 passengers per hour on average, or 200,000 during the morning peak period. This would translate to around 1 million extra heavy rail and Trackless Tram trips per day (500,000 in each direction).
According to Metro Report International there are a number of early movers in this autonomous shuttle space such as a trial on the Nanyang Technological University campus in Singapore using a system with “magnetic pellets on the road for navigation and a maximum speed of 40 km/h”, as shown in
Other examples include the City of Arlington, Texas, beginning trials on 2017 of the use of self-driving shuttles to provide services between the car parking area and the city’s entertainment district during large events. According to the Community Development and Planning Director for the City, John Dugan, “The pilot project will allow us to see how this driverless vehicle system really works and to look at the overall picture of how these vehicles could enhance the city’s transportation options.” Two self-driving shuttles provided by EasyMile will carry up to 12 passengers at a speed of 30 km/hr [
These factors all suggest that a Trackless Tram System (TTS) is likely to replace Light Rail and Bus Rapid Transit systems due to its ability to mimic all the best qualities of these systems while harnessing technology from High Speed Rail. The Trackless Tram can run rapidly in the road system but not cause the pollution and noise of BRT or the disruption and high construction cost of the LRT. The corridor system can be complimented by an electric shuttle service providing last mile/first mile interoperability as outlined. The significant cost reduction makes it highly attractive to fill the niche currently occupied by BRT and LRT with a TTS. Such a system is likely to provide a major reduction in car and bus
dependence while offering greater accessibility. However, there is one more major attraction of the Trackless Tram System that stands to provide a powerful drive for urban renewal and development. This is the city-shaping potential which is illustrated through two case studies in the following part.
The city shaping potential of a light rail or heavy rail has been well documented [
Effective and efficient corridor transit allows for a slowing of urban sprawl by facilitating greater urban density. This is demonstrated in the two cities. Firstly, a developed city, Perth, the capital city of Western Australia with a population of 2 million people that has sprawled over 150 km along the coastline and where various strategies have been proposed to increase redevelopment rather than greenfield sprawl, without success. Secondly a developing city, Thimphu, the capital city of The Kingdom of Bhutan with a population of 100,000 with aspirations to grow to 400,000 in a valley with very limited development space and hence where sprawl management is critical.
Perth has a history of automobile dependence since its strong urban growth period from the 1950’s onwards [
Thimphu has seen a rapid rise in automobile use and the subsequent consumption of petroleum fuels with both fully imported into Bhutan. According to the Asian Development Bank [
Considering the potential for slowing urban sprawl in Perth a proposal [
Parameter | Perth | Thimphu | Units |
---|---|---|---|
Predicted Additional Population | 120,000 | 300,000 | People (Ppl) |
Population Density (Fringe) | 12 | 40 | Ppl/Hectare |
Population Density (Corridor Stations) | 35 | 80 | Ppl/Hectare |
Additional Area Required (Fringe) | 100 | 75 | km2 |
Additional Area Required (Corridor Stations) | 34.3 | 37.5 | km2 |
Area saved by corridor transit approach | 65.7 | 37.5 | km2 |
Similarly, Thimphu, a city of 26 km2, plans to accommodate population growth from 100,000 to 400,000 people calling for the city to quadruple in size. Given the steep topography of the valley that the city is located in it is not an option to spread this out much beyond the footprint of the present city. It will be crucial for Thimphu to increase urban density in order to accommodate this population increase through urban re-development. As
Traffic congestion is an ongoing issue facing transport planners and network managers with levels of congestion growing to unworkable levels in many of the world’s cities, calling for alternative strategies rather than simply seeking to accommodate more automobiles. In 2015 alone Australia’s capital cities were estimated to have a combined congestion cost of $16 billion, expected to increase to $37 billion by 2030 [
Newman and Kenworthy [
Given the issues related to congestion, air pollution, and greenhouse gas emissions it makes sense to take advantage of higher capacity options, especially heavy rail, however connections down corridors using transit such as light rail or Trackless Trams would also be a much better transport option rather than accommodating more automobiles.
As outlined above there is a large land requirement associated with urban fringe development and lesser but still significant requirement for land to accommodate urban re-development. If a transport option can be enabled such as the system outlined in section 2.5 above, then there is a large reduction in the need for parking which can save up to a third of the land that then can be available for more productive urban uses. Considering the potential to reclaim car parking space in cities, the International Energy Agency [
To put this into context, in the proposed corridor transit project in Perth each of the 12 proposed stations would serve an estimated 10,000 residents who
Transport Mode | Average Passengers per hour per lane per km | Multiples of car capacity in a suburban street |
---|---|---|
Car in suburban street | 1000 | 1 |
Car in freeway lane | 2500 | 2.5 |
Bus in traffic | 5000 | 5 |
Bus in freeway lane (BRT) | 10,000 | 10 |
Trackless Tram (or Light Rail) | 20,000 | 20 |
Heavy Rail | 50,000 | 50 |
would require at the very most four parking spaces in the urban area they use rather than ten if they were on the fringe, saving a total of 9.3 km2 (based on minimum parking size requirements of 5.4 m × 2.4 m). In Thimphu rather than a 4 inner-city and 10 outer suburb parking allocations as is the case of Perth, it is assumed that there would be a reduced need of 2 inner city and 4 outer suburb car parks per person, with the proposed corridor transit system saving as much as 7.7 km2 of parking space, as shown in
A clear relationship exists between the density of employment and the proportion of new knowledge economy jobs [
According to Kane & Whitehead [
Parameter | Perth | Thimphu | Units |
---|---|---|---|
Predicted Additional Population | 120,000 | 300,000 | People |
Car Park Supply (Urban Fringe) | 10 | 4 | Ppl/Hectare |
Car Park Supply (Corridor Transit) | 4 | 2 | Bays/Hectare |
Additional Parking Area Required (Fringe) | 15.6 | 15.4 | km2 |
Additional Parking Area Required (Corridor) | 6.2 | 7.7 | km2 |
Area saved in a corridor transit approach | 9.3 | 7.7 | km2 |
could not have been generated with one firm alone. For individuals, they have access to the opportunities that this rich cluster of productivity and innovation enables.
Newman and Kenworthy [
In addition to car-related environmental impacts, greenfield expansion on the urban fringes is also commonly cited as the cause for loss of farmland, open space, forest and habitat [
The advent of the Trackless Tram System now makes urban re-development and higher densities to be far more achievable and affordable for cities around the world, especially in the developing world.
With transport constituting approximately 23 percent of global energy-related greenhouse gas emissions [
The World Health Organisation (WHO) released data in 2016 showing that an estimated 4 in 5 people living in monitored urban areas are exposed to air quality pollution that exceeds recommended levels [
In addition to air pollution benefits a shift to corridor transit will reduce vehicle collisions and road fatalities. According to the WHO more than 1.3 million people die annually on the road in the world and another 20 - 50 million are injured. A study by the WHO and the Asian Development Bank found that Bhutan is second only to Nepal in the number of road deaths per 10,000 vehicles. To compound this social challenge, neighbourhoods of lower-socio-economic status generally tend to have the highest motor vehicle collision rates [
The need for cities to engage their citizens and provide equitable solutions for their future has been a major thrust of the New Urban Agenda [
As this paper has shown there are multiple benefits that can be achieved by implementing a Trackless Tram System as the basis of city shaping. The Trackless Tram System is likely to contribute to most of the SDG’s especially the need for an “inclusive, safe, resilient and sustainable city” not just because of its technology but because it enables city shaping. The need for urban regeneration to create new centres of urban activity is now a high priority for most cities. The Trackless Tram has all the qualities to enable such densities and mixed urban activity to be attracted to station precincts. These Transit Oriented Developments are not new in concept but are hard to deliver unless made into a whole corridor of urban regeneration. According to Newman et al. [
The best way to draw together the character and potential of a Trackless Tram System is to compare it to Light Rail and Bus Rapid Transit systems.
Others looking at the characteristics in
The Trackless Tram System is a new kind of transit system that has been generated by crossover innovations from High Speed Rail being applied to a bus. It is neither a Tram nor a Bus though it has the speed/capacity, ride quality and land development potential of a Tram and the cost, lack of disruption and rapid implementation of a Bus. It is therefore a new kind of transit technology that offers radical and transformative opportunities for cities needing connection across suburbs and electric accessibility that unlocks urban regeneration. The Trackless
Characteristic | Bus Rapid Transit (BRT) | Light Rail Transit (LRT) | Trackless Tram System (TTS) |
---|---|---|---|
Speed and Capacity | ü | üü | üü |
Ride Quality | û | üü | üü |
Land Development Potential | û | üü | üü |
Cost | ü | û | ü |
Disruption during construction period | ü | û | üü |
Implementation Time | ü | û | ü |
Overall | ü | üü | üüü |
Tram System presents a tangible and affordable opportunity for cities around the world to combat automobile dependence while providing an obvious economic opportunity for harnessing new land development potential. By harnessing technologies applied in various other forms of autonomous and high technology transport, the Trackless Tram System presents a new and unique transit option that can not only incorporate cutting edge technology but deliver significant economic, social and environmental benefits to the worlds’ growing cities.
The authors declare no conflicts of interest regarding the publication of this paper.
Newman, P., Hargroves, K., Davies-Slate, S., Conley, D., Verschuer, M., Mouritz, M. and Yangka, D. (2019) The Trackless Tram: Is It the Transit and City Shaping Catalyst We Have Been Waiting for? Journal of Transportation Technologies, 9, 31-55. https://doi.org/10.4236/jtts.2019.91003