SFO's bigger problem is not the intersecting runways, but the parallel runways that are too close together (only 750' apart). Only 2 runways are used for arrivals on a good day (59 per hour) - when the visibility diminishes or wind changes direction, we get only 30 arrivals an hour. This means your Shuttle flight may not leave until tomorrow. (But your flight to LHR will probably be A*OK)