What effect does a dual parallel runway configuration have on operations?

A dual parallel runway configuration significantly enhances airport operational efficiency, particularly by allowing simultaneous Instrument Flight Rules (IFR) approaches. This configuration typically involves two runways that run parallel to each other, which may be spaced adequately apart to accommodate aircraft operating under IFR, thereby optimizing air traffic flow and increasing the number of aircraft that can land or take off simultaneously.

The effective use of dual parallel runways under IFR conditions is essential, especially in busy airports, because it reduces congestion, minimizes delays, and improves overall capacity. This capability is particularly crucial during inclement weather when aircraft must rely on instrument approaches rather than visual references. As a result, the utilization of dual parallel runways is integral to maintaining efficient airport operations and safety.

The other options do not correctly describe the effects of a dual parallel runway configuration. For example, restricting operations to daytime and permitting only visual landings do not align with the advantages provided by dual parallel configurations, especially under IFR conditions. Similarly, operating limitations under specific altitudes are unrelated to the capabilities that parallel runways offer.