# The Railways and Other Guided Transport Systems (Safety) Regulations 2006, Paragraph 14: Measurement units for NRVs and CSTs


The following table sets out the measurement units for NRVs and CSTs.
Risk category
Measurement units
Scaling bases
1. Risks to passengers
1.1 Number of passenger FWSIs per year arising from significant accidents/Number of passenger train-km per year
Passenger train-km per year
1.2 Number of passenger FWSIs per year arising from significant accidents/Number of passenger-km per year
Passenger-km per year
2. Risks to staff or employees, including the staff of contractors
2. Number of employee FWSIs per year arising from significant accidents/Number of train-km per year
Train-km per year
3. Risks to level crossing users
3.1 Number of level-crossing user FWSIs per year arising from significant accidents/Number of train-km per year
Train-km per year
3.2 Number of level-crossing user FWSIs per year arising from significant accidents/[(Number of Train-km per year x Number of level crossings)/Track-km)]
(Train-km per year x Number of level crossings)/Track-km
4. Risks to others
4. Yearly number of FWSIs to persons belonging to the category ‘others’ arising from significant accidents/Number of train-km per year
Train-km per year
5. Risks to unauthorised persons on railway premises
5. Number of FWSIs to unauthorised persons on railway premises per year arising from significant accidents/Number of train-km per year
Train-km per year
6. Risk to society as a whole
6. Total number of FWSIs per year arising from significant accidents/Number of train-km per year
Train-km per year

---
Source: https://www.legislation.gov.uk/uksi/2006/599/schedule/11/paragraph/14 (the official version)
Page: https://openlegislation.uk/railways-and-other-guided-transport-systems-safety-regulations-2006/schedule-11/paragraph-14
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.