... de facto: nobody tried, or even looked for a general solution. Myriads of partial cures are proposed, from inserting ever more expensive and inconclusive buses/metro/trams/highways or complex "smart" arrangements - none of them intended to create a SYSTEM thus resulting in ever more cars and GHG.
Our criterion for a sustainable urban transport: that it get rid of automotive, at last.
This humanized city goal is only approached in modern pedestrian areas, because on the lack of an efficient replacement for cars/delivery which are only pushed a few hundred meters away, and in most cases allowed at night. When we talk about zero-car it means they keep kilometres outside.
In the CarLina car-free area, the maximal speed is that of pedestrian. Loads, freight, disabled people, waste are gently carried at walk pace over the last 100-150m using ordinary load handling chariots.
In some larger avenues is the elevated network installed. It is silent, clean, much quicker than anything nowadays overfilling cities. It carries people and goods, effectively rendering private & delivery cars obsolete.
The solution is simple, much cheaper and efficient than anything currently proposed, and is designed for public-domain use.
"over a 2D perimeter, move whatever now takes streets and roads optimally from A to B with constraints:
- 24/7 operation, 1mn waiting time.
- point-to-point transport like the automotive (-is perceived to)
- zero emissions, including pollutants and noise
- aesthetic, comfortable, sustainable
- conserving the feeling of security one may have in its own car
- cheap to develop, deploy, own, operate, maintain, evolve, dispose, recycle"
Not PRT. The above expression of requirements is extremely close to that of an electronics printed circuit board. Look at the amazing equivalences:
- transporting digital frames (=vehicles)
- packing bit sets (=people, waste bins, parcels, packets, loads), what engineers call "payload"
- do that on a 2D area the complexity of a city, the printed circuit board
- with the best latency (=waiting time) and bandwidth (capacity)
- while generating no noise (=no noise) and minimizing consumption (=oil)
- applying proper scheduling to even "evenmential requests" (=guaranteed no congestion)
- transport things (frames and bits) in absolute safety
- best done along serial lines (=streets)
This problem was correctly solved for decades, or no PC or phone would work. The best possible implementation of this knowledge, AIDA, is general and versatile enough to be directly transposed to the urban transport problem. An extremely rigorous scheduling method, just computing in advance any travel to the millisecond, is effective and compatible with anybody suddenly wanting to reach B from A.
From the user's point of view, the network is totally asynchronous and available on demand. From the system point of view, all travels are just behaving as scheduled, and scheduled they are such that congestion is an unknown concept, "missions" are always the fastest possible and burn the theoretically minimal energy.
Everything that isn't available now, to make a long story short.
Just like cars were designed: imagine if they were bus-sized what flexibility resulted? Never would have they conquered the world.
Outdating the automotive implies the ability to transport on minute notice someone (and CarLina does more: something) at 3AM. never shall it be done with buses/tram/metro/train because 1) they cannot be available then and everywhere 2) there's no way this is profitable 3) this would be such a nuisance.
On the contrary a 2 meter long (smaller than a SMART ForTwo) pod, waiting for you the time it takes to reach the station shall go silently and even unnoticed, lights out, faster than all PTs wherever in the entire area, or at its border where cars are parked. A second pod could accompany the passenger's one with almost one ton of baggage.
More generally, small vehicles are light, which translates into way cheaper infrastructures, they can pass everywhere a car does, do not require digging huge trenches across a city, can be ready instantly when people use to patiently wait for buses to pass by. Fleet can increase and diminish quickly along with traffic demand.
Contrary to popular belief ***, it would be extraordinarily difficult and costly to operate an autonomous vehicle in a real city, and attempts in this direction will lead to expelling all pedestrian activity, which is the opposite of a desirable conclusion.
A more desirable, and in fact sustainable way, is to keep ground areas for pedestrian/biking activities and move the traffic below or over. Below (tunnels) is very expensive and not modifiable once done, a terrible responsibility for the city planner. Elevated trackways are the best solution, from an urbanistic, engineering, financial and even visual point of view.
And because the CarLina system is complemented on ground with a last-200m reaching part, elevated tracks don't have to be visible everywhere, only on larger streets that are now full of noise, pollution, trucks, tram overhead cabling etc. and would be reconquered for green use.
*** to fund-raising communication, actually
Since public transports definitely disdain carrying goods like palettes to/from shops, the disabled, waste bins... everything the automotive do, they are enforcing an infinite choking of cities by private and delivery automotive.
In the CarLina system, autonomous platforms operate regardless of what load is put upon. Standard passenger cabins are designed for receiving the disabled and lift them up/down in sort that they can access the network at each station just like a normal elevator, with a minute waiting time and delivery to the second whatever the destination.
The multi-purpose standard station lift can accommodate raw loads as shown above, palettes, standard containers. Platforms fitted with street work devices can collect the garbage and bring back waste containers that people put at dedicated places.
Network: contrary to popular belief it doesn't exist such thing as a metro or even a bus network. There are lines that become a network thanks to users' feet performing connections at some stations.
In the CarLina concept, this deriving from PRT works, a true point-to-point service is offered, in fact it would be more difficult to mimic the inefficient scheduling of the today so-called urban "networks".
Distance between stations: in a given social culture, there is a "refusal distance" to access a transport mode beyond which the user shall change its mind (ie take a car). In rich occidental cities this is about 100m and this is why bus stops will be set 200m apart.
In the CarLina system stations are spaced like bus stops, in order for users to have one 100m away from home. simple handling chariots are pulled on a "leash" by local people to perform the last 100-150m delivery and special handling (like a disabled person, a ton of bricks...).
Cost model: the expensive part of a network at its deployment phase is in trackways. To keep that cheap, CarLina trackways are passive, not even having switches, just steel and a light but extremely efficient AIDA communication network for pods to manage everything from real-time (soft) crash management to mission bookings.
Costly railway elements like signalising systems and control centres are unknown in this cellular automaton.
Trackways are made of self-supporting (in the mechanical and logical senses) elements who communicate with immediate neighbours and passing by pods.
Any track element continuously analyses its own behaviour on that of passing pods, the resulting mass of data feeding an extremely well documented distributed health management system.
Each pod monitors and directly communicates with its neighbours, and with the entire network through the trackways network.
Pods in turn continuously analyse and check their neighbours and the tracks, collecting parameters like the detailed status of the surface, structural responses, communication etc.
No other communication or "intelligence" is required, making the CarLina network a distributed system with safety and robustness levels vastly beyond anything deployed nowadays.
Controlling the pod is a small AIDA network made of six nodes:
- one in each wheel (x4), in charge of propulsion, ground interfaces, braking.
- bow/stern ones (symmetrical/reversible) in charge of inter-pod communication, monitoring and contact, trajectory safety and law of motion.
Note: CarLina being totally distributed, there is only a single law of motion for all the (or any) network
The safety and performance level of such a six-nodes AIDA system far exceed usual rail/aerospace standards, which is consistent with the absence of an external, central control system for CarLina networks.
Architecture, demonstration and feasibility works in 2016 concentrate on three strategic topics:
A CarLina vehicle or "pod" is made of two parts 1) the autonomous platform 2) a functional load, in configurations:
Pods coordinate with each other to automatically perform any mission.
A mission possibly consists of 4 platforms with handling interfaces teaming up to catch, transport, deliver a 20' container, where platforms involved only use the trackway communication network to perform real-time, millimetric synchronization.
Mainly: mechanical support, maintaining a seismic-proof trajectory, obstacle clearing, anti-intrusion, energy supply, network communication.
Optimized for the lowest possible sustainable cost, tracks are made of recyclable steel and are bent to an ideal 3D trajectory to both eliminate operating noise and bring energy consumption to an absolute low. This in turn makes for the lowest possible transportation cost, to the point that SEA proposes standard networks for free use.
Pods share kind of a Taxi mentality, sharing their availability for any request. Each pod learns which parts of the network is best for it to load clients.
The network measures and checks passing pods.
Pods measure and check tracks and other pods.
Only pods recognized by their peers are allowed in the network, imperfect/suspicious ones are compelled to maintenance.
New pods or repaired/checked ones are accepted in the network with some mistrust until mutual checking is automatically conducted by other pods and trackways.
Curing a problem requires the identification of its root cause. Astonishingly, urban congestion has never been analysed as a theoretical problem: maybe because urban automotive congestion is a good business, let's mention a few aspects of this:
It should be also mentioned in the side effects that local authorities have been culturally deprived of their ability to decide what technical/urbanistic decision is the best and conclusive for themselves. All what they are only requested is to open the access to public money.
As usual once the cause is known, the solution comes easy