The bumping block is probably installed as a safety measure so an errant car wouldn't roll out onto New Highway. While the basic configuration of the tracks creates a wye, the chance to turn anything on it is probably zero since Coastal occupies one half of it. Coastal never uses the west leg. Due to FRA regs they can only access the east leg themselves. As I've mentioned the west leg of the wye was always a dangerous proposition anyway because you can back up traffic over the main line, causing the potential for a fatal wreck. (There was specific rules in the LIRR Special Instructions regarding using the west leg because of this.)
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