SOURCE-LINKED REGULATION GUIDE
UN R171 — Driver control assistance systems
Distinguish DCAS from other steering-assistance functions.
Explore the scopeWhat does it cover?
UN R171 addresses type approval of M and N vehicles with regard to driver control assistance systems (DCAS). This version explains its relationship to automatically commanded steering and risk-mitigation functions approved under R79. Whether the manufacturer declares such a function to be part of DCAS affects which scope applies.
Who is it for?
Driver-assistance, vehicle-control and homologation teams.
Which subjects are addressed?
- DCAS vehicle approval
- M/N scope
- Relationship to R79 functions
- Manufacturer system declaration
Common question
Is a function approved under R79 always outside R171?
No. R171 applies if the manufacturer declares that function to be part of DCAS. A prior approval name alone does not determine the system scope.
Source documents and references
Work with this regulation in RegsUP.
Read the text with its edition and sources. Assess available comparisons, relevant dates and question-and-answer features against your work needs.
Discuss access optionsRelated regulations
UN R79 — Steering equipment
Assess steering systems against their scope and exceptions.
UN R157 — Automated lane keeping systems
Review the ALKS function together with transfer of control to the driver.
UN R155 — Vehicle cybersecurity
Assess vehicle-type requirements alongside the cybersecurity management system.