What is the advantage of HIRL or MIRL on an IFR runway compared to a VFR runway?

The advantage of High-Intensity Runway Lights (HIRL) or Medium-Intensity Runway Lights (MIRL) on an IFR runway compared to a VFR runway is primarily related to visibility and safety in approach and landing phases during instrument flight conditions. In particular, the use of amber lights in the last 2,000 feet of the runway serves as a visual cue to pilots, indicating a caution zone.

This design helps to enhance the pilot's awareness of the runway's length and the termination point where the solid white lights transition to amber, thereby alerting them to reduce speed or prepare for potentially complex landing dynamics. This differentiation is crucial in Instrument Flight Rules (IFR) scenarios where reduced visibility can make distinguishing between various lighting systems more challenging.

Additionally, while alternate red and white lights may be featured in certain contexts, they serve a different purpose and do not specifically indicate a caution area in the same way that amber lights do. The statement regarding lights being closer together relates to the configuration of airport lighting but does not highlight the unique safety benefit provided by the specific color coding of lights on IFR runways. Hence, amber lights play an essential role in guiding aircraft safely during critical landing procedures, particularly in low visibility conditions.