Lighting and signalling — typical flash rate for turn indicators For an automotive side-turn indicator, what is the usual flashing frequency (flashes per minute)?

Introduction / Context:
Turn indicators must flash within a regulatory frequency band to ensure recognisable signalling to other road users. The typical design target is near 90 flashes per minute.

Given Data / Assumptions:

• Passenger vehicle turn indicators.
• Standard automotive flasher modules or BCM-controlled flashing.
• Ambient conditions nominal.

Concept / Approach:
Most standards specify a range (for example, roughly 60 to 120 flashes per minute). Manufacturers commonly calibrate around the middle of the band, near 90 fpm, for visibility and compliance.

Step-by-Step Solution:
Recognise typical regulation band.Select the central common value: approximately 90 fpm.

Verification / Alternative check:
Automotive service literature and indicator relay specifications often list nominal 90 ± 30 fpm.

Why Other Options Are Wrong:

• 9: far too slow.
• 900 or 9000: orders of magnitude too fast.

Common Pitfalls:
Confusing flashes per minute with hertz. 90 fpm corresponds to 1.5 Hz.

Final Answer:
90