Invited talk at WOSP-C 2021

1. Performance and safety challenges of
the next generation railways
Stefano Marrone
Dipartimento di Matematica e Fisica
Università della Campania «Luigi Vanvitelli»
Caserta - Italy

2. Overview
• The evolution of railways
• The ERTMS standard
• Research & funding programmes
• The PERFORMINGRAIL project
• Future Railways – challenges
• Moving block
• Virtual coupling
• IA & Railways
• The two faces of the security
• Interoperability (not what you’re thinking about….)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

3. Stefano Marrone
• Assistant professor @Università della Campania «Luigi Vanvitelli»
• Professional background in railway industry
• Research interests:
• V&V of critical systems
• Application of formal methods in industrial settings
• Model-Driven Engineering
• Domains
• Healthcare
• Industrial Control Systems
• Railway Signalling (this was easy )
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

4. WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Evolution of Railways

5. Railways in ‘20s (1920)
• Focus on the network
• What about speed??
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Schwartz, Robert & Gregory, Ian & Thevenin, Thomas. (2011). Spatial History: Railways, Uneven
Development, and Population Change in France and Great Britain, 1850–1914. Journal of Interdisciplinary
History - J INTERDISCIPL HIST. 42. 53-88. 10.1162/JINH_a_00205.

6. Railways in ‘20s (2020)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
There is at least one technology in America,
however, that is worse now than it was in the
early 20th century: the train.
https://slate.com/human-interest/2009/05/why-trains-run-slower-now-than-they-did-in-the-1920s.html
But it was not uncommon for the Zephyr or other
trains to hit speeds of more than 100 mph in the
1930s. Today's “high-speed” Acela service on
Amtrak has an average speed of 87 mph and a
rarely hit peak speed of 150 mph. (The engine
itself could top 200 mph.)
How to
conciliate?

7. The many faces of railways (I)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

8. The many faces of railways (II)
• Speed
• Safety
• Interoperability
• technical
• process
• Capacity
• Availability
• structural
• service
• Security
• physical
• security
• Energy saving
• User experience
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
International
standards rule!
Rate of dangerous
failures per hour
(THP)
Rate of dangerous failures per
hour (THR)
Safety Integrity Level
< 10-10 < 10-8 4
< 10 -8 < 10-7 3
< 10-7 < 10 -6 2
< 10 -5 < 10 -5 1

9. WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Standards in Railways

10. The role of the standards
• To foster interoperability
• To define acceptable risk assessment processes & criteria
• To provide guidelines & constraints for design and V&V processes
• To provide a proper separation of concerns among railway features
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

11. Computer-based Railways
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Movement
Safety
Routing

12. European Railway Traffic Management
System (ERTMS)
Objectives
• to create Core Network Corridors
https://ec.europa.eu/transport/infrastructure/tentec/tentec-portal/map/maps.html
• 50.000 Km by 2030
• Not only in Europe (51 worldwide countries)
Two main components:
• European Train Control Systems
• GSM-R
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

13. ERTMS
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

14. ETCS
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Three main objectives:
• Technical interoperability (on-board / trackside)
• Safety increase
• Train speed & lines capacity improvement
• Three levels (L1 to L3)

15. ETCS
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Communication Track Occupation Outdistancing
L1 Discontinuous
Trackside Fixed Block
L2
Continuous
L3 Train Integrity Moving Block
https://www.youtube.com/channel/UCqstCekSABvo3bq7GjRA0Og/videos

16. WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Research & funding in Railways

17. Research in railways
«Railways», CS/MATH/ENG, 2015+
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

18. Research in railways – papers per countries
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

19. Research in railways – international
collaborations
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

20. Research in railways – academy-industry
collaborations
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

21. Research in railways – first quartile
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

22. Funding programme – Shift-to-Rail
• 16 December 2013: Publication by the European Commission of a legislative
proposal to launch SHIFT²RAIL, an ambitious new European Research &
Innovation Programme that aims to:
• Increase the competitiveness of the EU rail industry to help it retain world leadership
• increase the attractiveness of rail transport.
• A future public-private Joint Undertaking under Horizon 2020
• Proposed budget of 920 Million Euros for 2014-2020, including 450 Million
from the EU and 470 Million from the Industry
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

23. Funding programme – Shift-to-Rail
• Innovation Programs
• IP1 – rolling stocks (traction and braking system)
• IP2 – command & control (moving block, virtual coupling)
• IP3 – train infrastructure
• IP4 – service (smart ticketing, multimodality)
• IP5 – freight market
• CCA (cross cutting activities)
• IPX – (think about a current buzzword…)
• Two kinds of projects (member calls and open calls)
• Coupled projects
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

24. Funding programme – Shift-to-Rail
• What about 2050?
• Passenger traffic
• The majority of medium-distance passenger transport should go by rail
• High-speed rail outpacing the increase in aviation for journeys up to 1000 km
• By 2050, connect all core network airports to the rail network
• Freight traffic
• Greater use of more energy-efficient modes – 30% of road freight over 300 km should
shift to other modes by 2030, and more than 50% by 2050
• Rail freight almost doubled – +360 billion ton-km (+87%) compared to 2005
• Deployment of ERTMS
• By 2050, connect all seaports to the rail freight system
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

25. • Definition of Specifications for safe and performing moving block operations
• Formal modelling of moving-block specifications
• Identification of Moving-block hazards
• Development of Fail-safe train localisation solution
• Design of Future Traffic Management Architecture for Moving-Block
• Implementing of a Moving-block testing platform
• Proof-of-concept and Assessment of moving-block specifications and models
• Recommendations for safe and performing moving-block configurations
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
@PerformingRail
www.performingrail.com
PERformance-based Formal modelling and Optimal
tRaffic Management for movING-block RAILway
signalling
S2R-OC-IP2-01-2020
from 01/12/2020 to 30/06/2023
Coordinator: Lei Chen (University of Birmingham)
Complementary projects: X2RAIL-5, X2RAIL-3

26. WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
Preliminary safety analysis & hazard list
Fail-Safe Train Positioning
Formal Methods (taxonomy and survey)
Fail-Safe Train Positioning
Formal models & hazards
Moving Block
Operational and
Engineering Rules
Operational Scenarios for
Virtual Coupling
Specification of formal
development demonstrator
Related S2R projects

27. WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
The challenges

28. Moving block
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Needs
• improve the capacity of the
lines
• Facts
• Position is given by the
infrastructure and not by
train
• Increasing track circuits
granularity  not
sustainable
C. Tyler Dick et al., Relative Capacity and Performance of Fixed- and Moving-Block Control Systems on North American Freight Railway
Lines and Shared Passenger Corridors, Transportation Research Records, 2019

29. Moving block (challenges)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Train Integrity Monitoring Systems
• being aware of a train losing its parts in
SIL4 (THR < 10-8)
• GNSS
• Inertial Measurement Unit (IMU)
• Pipe-Brake
• Ensemble methods!
https://business.esa.int/projects/3tims

30. Moving block (challenges)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Positioning (standard requirements)
• Accuracy of distances measured on-board: for
every measured distance s the accuracy shall
be better or equal to ±(5m + 5% s)
• Accuracy of speed known on-board: ±2 km/h
for speed lower than 30 km/h, then
increasing linearly up to ±12 km/h at 500
km/h.
• Age of speed and position measurement for
position report to trackside: the speed and
the position of the train front indicated in a
position report shall be estimated less than 1
sec before the beginning of the
corresponding position report.

31. Moving block (challenges)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Technologies
• GNSS
• Odometry
• Balises
• In station
• GNSS localization in station could be difficult
because of a poor or blocked sky visibility and
the presence of multipath.
• At the start of mission, on-board odometry
and/or inertial systems are useless in the
absence of an absolute position
• The localization in station is required to be
especially precise.
• In tunnels
• No GNSS
• inertial solution may drift and such drift is
dependent on the length of the tunnel.
• In proximity of major railway exchanges and
parallel branches
• GNSS standalone could have difficulty in
achieving the necessary accuracy to discriminate
among several close tracks.

32. Moving block (challenges)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Communication
• Not those holes
• Trackside needs to know the position
• Conservative track reservation mechanisms
• How to solve?
• Failures
• RBC must hold disconnected train information (different from L2)
• What happens if RBC fails?
• Mixed-traffic modes
• Ghost train (train with no radio communication)
• Shadow train (ghost train following a L3 train)
Sweeping Train

33. Moving block
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Where
• Now: metro lines (Computer-based Train Control)
• Future: heavy railways, freights
• Advantages
• Train headway is halved with respect to three-aspects signalling
• Doubled line capacity
• Reduce infrastructure costs (-18% of maintenance costs London
Tube)
• Energy saving (15% of energy in Metro Paris)
• Improve availability

34. Virtual coupling (a.k.a. soft-wall moving block)
• Needs
• Improve the capacity of the lines (again!)
• Facts
• Same concept of platooning in vehichles
• Relying on Moving Block
• A Train Convoy or Virtual Coupled Train Set (VCTS) is a formation of virtually coupled
trains is viewed as one train by the interlocking systems.
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

35. Virtual coupling (challenges)
• High business risks
• it’s hard to estimate
• Is it worthy?
• High technological risks
• Risk are worsened by hazards impact
• V2I/V2V communications
• Fast communications
• Cybersecurity first!
• Availability issues
• Critical scenarios
• Joining
• Splitting
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

36. Virtual coupling
• Where
• Future: everywhere (theoretically!)
• Advantages
• Capacity increase
• Mainline (from 15% to 30%)
• Freights (from 25% to 50%)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

37. AI & Railways
• Needs
• Improve quality and lower costs (an easy target!!)
• Facts
• CENELEC standards do not foster non-verifiable techniques
• Strong design and programming guidelines
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

38. AI & Railways (challenges)
• Trustwortht AI
• Ethics, Privacy, Respect for the freedom
• Prevention of any kind of harm, fair, explainable
• …. But what is «human» behaviour?
• Emergent Behaviour
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
https://www.nature.com/articles/d41586-018-07135-0

39. AI & Railways (challenges)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Emergent behaviours
• ATO: computer visions in
urban contexts
• Predictive maintenance:
certification vs IoT

40. AI & Railways
• Where
• rail safety and automation (driverless ATO)
• predictive maintenance and defect detection
• traffic planning and management
• No signalling, please!!!
• Advantages
• Too many to enumerate but will it be technically feasible? Legally feasible? And
worthy?
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

41. Security
• Needs
• to continue keeping
people (& service)
safe and operative
• Facts
• Threats may be
physical, cyber or
phygital
• Some protocols
adopted in railways
would be banned in
other domains….
TripleDES!!!
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

42. Cybersecurity (research)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Key Management Systems
• ERTMS standard
• Full (secure) interoperability
• Online/offline standard
• Online authentication is far from being
implemented
• Next goals: change of mind-set
• Cybersecurity practices in the rail sector are
evolving. Cybersecurity is slowly being
integrated into the design of IT and OT for
transport systems. Cybersecurity culture builds
up among rail stakeholders, both OES and
their suppliers. [ENISA].

43. Security(s)
• Where
• All configurations: metro, high speed,…
• Advantages
• safety,
• service availability,
• increase traffic (due to an increased perception of
security)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

44. Interoperability
• Needs
• Unifying modelling and analysis approaches in different contexts
• Facts
• Each national authority has its own signalling system
• ERTMS does not cover national signalling
• At each technological innovation there is a reinvention of the wheel!!
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways

45. Interoperability – Reference CCS
architecture
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
• Rail System Model
• topo[logy|graphy]
• For graph walking algorithms
• Positioning algorithms
• Track alignment
• For energy optimal driving
• EULYNX
• All you need to build the Signalling
system
• Routes
• Overlaps
• Signalled (ETCS) profiles
• Gradient
• Speeds
• Transforms into XSD, C#, …
dataprep.eulynx.eu

46. Interoperability (advantages)
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
“It is unworthy of excellent men to lose hours like slaves in the
labour of calculation which could safely be relegated to anyone
else if machines were used.”
― Gottfried Wilhelm Leibniz

47. Contacts
WOSP-C, 20/04/2021, on-line S. Marrone - Performance and safety challenges of the next generation railways
stefano.marrone@unicampania.it