Synergies Between PRT and Driverless Cars
Prof. Em. Ingmar Andreasson
LogistikCentrum AB
Ingmar Andreasson
• Bus network planning 1970:ies
• Taxi fleet management 1980:ies
• Driverless transit since 1990:ies
• PRT design and control patents
• Professor Traffic simulation KTH
• Vice President Advanced Transit Association
New transport modes are needed
• Use of private cars has decreased
• Fewer youngsters take driver’s license
• Car industry in crisis
• Energy crisis
• Climate crisis
• Congestion
• Lack of space for roads and parking
Peak car (Britain)
Some development trends
• Electric cars
• Car-sharing
• Co-modal trip planners
• Autonomous cars
• Driverless transit
Google car
NHTSA Levels of automation
• L1: Function specific (ex: braking)
• L2: Combined functions (ACC+lane)
• L3: Limited self-driving – Driver can cede control under conditions– Google car, platoons
• L4: Self-driving – Can run empty, shared or public– In parking lots, reserved lanes
SARTRE project
0.3 sec headway (6 m gap) @ 85 kph in mixed traffic
Driverless transit
• Vehicles can be small
• Short headways
• Individual, on demand
• Non-stop between transit stops
• Reserved right-of-way
⇒Personal Rapid Transit
Morgantown PRT since 38 years
• 73 vehicles
• 80 million passengers
• No serious accident
Modern PRT
• Small, light
• Short headways
Automated Transit Networks (PRT)
• Steering, braking, navigating since 1975
• Reserved lanes or separate “roads”
• Empty repositioning by demand
• Excellent safety
• Available to all (age, disabilities, license)
• Low energy, no pollution
Synergy contributions from cars
• Resources for development
• Low-cost sensors
• Better batteries
• Economies of scale
• Communication protocols
• Acceptance of short headways (0.3 vs 3 secs)
• Strong industry lobby
Economies of scale
100 000 € 100 000 € 30 000 €
Contributions from PRT
• 38 years operating experience
• Proven safety
• Standards and certification
• Ride-sharing strategies
• Empty vehicle management
• Safe and smooth intersection control
Ride-sharing patterns
O D1 D2
Same destination
Two destinations
Two & pick-up
(Pick-up & continue)
Vehicle surplus/deficits
Vehicles in station
– Vehicles allocated to depart
+ Vehicles (loaded or empty) on way in
– Passenger parties waiting
– Expected passengers during call time
Management of empties
1. Call/send based on surplus/deficit
2. Swap destinations so longest waiting
passenger gets nearest
3. Send remaining to largest deficit
Intersection control
• Approaching vehicle calls controller
• Controller allocates passage time-slot
• Notice of passage time sent to vehicle
• Vehicle adapts speed to fit slot
• Individual greens to pass
• = Merge control in asynchronous PRT
Dual-Mode
Car development
• Manual plus Driverless on guideway
PRT development
• Guideway PRT plus manual control
⇒Convergence of Car and PRT
Dual-mode cars
Dual-Mode is attractive
• Door to door travel
• Guideways and access can be widely spaced
• Need not be connected to network
• Attractive along arterials with queues
• Allows gradual implementation
• Vehicles private – less public investment
• No operator – V2V control
• Public system possible on guideways
Dual-Mode infrastructure
• Guideway = public road
• Relieving road congestion
• Open for equipped and checked vehicles
• For small vehicles only
• Less investment than new roads/lanes
• Small footprint
• Suitable for battery charging and debiting
Conclusions
• Embrace Driverless Cars and PRT
• Developments supporting each other
• Both converge into Dual-Mode
• Network of reserved roads/lanes/guideways for
autonomous vehicles
• Private and public transport on same network
• Automated taxi – “aTaxi”
• Eventually in mixed traffic
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