A rail junction assembly for directing first and second rail vehicle wheels of a wheel arrangement, the first and second wheels having respective first and second flanges, the rail junction assembly comprising: first and second main rails (12, 14); first and second switch rails (16, 18); a first flange receiving passage defined between the first switch rail and the first main rail, and a second flange receiving passage defined between the second switch rail and the second main rail; wherein the first flange receiving passage is configured to receive the first flange of the first wheel, and the second wheel can transfer between the second main rail and the second switch rail when the first flange is received in the first flange receiving passage, and wherein the second flange receiving passage is configured to receive the second flange of the second wheel, and the first wheel can transfer between the first main rail and the first switch rail when the second flange is received in the second flange receiving passage; a guide arrangement for guiding the first flange of the first wheel into, or out of, the first flange receiving passage, and for guiding the second flange of the second wheel into, or out of, the second flange receiving passage, the guide arrangement being moveable to a first guide condition for guiding the first flange into, or out of, the first flange receiving passage, and the guide arrangement being moveable to a second guide condition for guiding the second flange into, or out of, the second flange receiving passage; characterized by further comprising a wheel control arrangement for controlling the first wheel on the first main rail and on the first switch rail when the second flange is received in the second flange receiving passage, and for controlling the second wheel on with the second main rail and on the second switch rail when the first flange is received in the first flange receiving passage; wherein the wheel control arrangement is configured to engage the wheel arrangement when the guide arrangement is in the second guide condition to maintain the first wheel in engagement with the first main rail when the first wheel transfers between the first main rail and the first switch rail, and is configured to engage the wheel arrangement when the guide arrangement is in the first guide condition to maintain the second wheel in engagement with the second main rail when the second wheel transfers between the second main rail and the second switch rail. first and second main rails (12, 14); first and second switch rails (16, 18); a first flange receiving passage defined between the first switch rail and the first main rail, and a second flange receiving passage defined between the second switch rail and the second main rail; wherein the first flange receiving passage is configured to receive the first flange of the first wheel, and the second wheel can transfer between the second main rail and the second switch rail when the first flange is received in the first flange receiving passage, and wherein the second flange receiving passage is configured to receive the second flange of the second wheel, and the first wheel can transfer between the first main rail and the first switch rail when the second flange is received in the second flange receiving passage; a guide arrangement for guiding the first flange of the first wheel into, or out of, the first flange receiving passage, and for guiding the second flange of the second wheel into, or out of, the second flange receiving passage, the guide arrangement being moveable to a first guide condition for guiding the first flange into, or out of, the first flange receiving passage, and the guide arrangement being moveable to a second guide condition for guiding the second flange into, or out of, the second flange receiving passage; characterized by further comprising a wheel control arrangement for controlling the first wheel on the first main rail and on the first switch rail when the second flange is received in the second flange receiving passage, and for controlling the second wheel on with the second main rail and on the second switch rail when the first flange is received in the first flange receiving passage; wherein the wheel control arrangement is configured to engage the wheel arrangement when the guide arrangement is in the second guide condition to maintain the first wheel in engagement with the first main rail when the first wheel transfers between the first main rail and the first switch rail, and is configured to engage the wheel arrangement when the guide arrangement is in the first guide condition to maintain the second wheel in engagement with the second main rail when the second wheel transfers between the second main rail and the second switch rail.