I just realised, even better would be for Emperors and Empresses (only) to upgrade to using an Imperial Carriage (which would be kind of slow). Some of its characteristics, taken from Records of the Grand Historian: "I have always been told that only the most distinguished men of the empire are privileged to ride with the Son of Heaven in his six-foot carriage", "Your Majesty proposes to gallop down a steep slope in a carriage drawn by six horses", "He then began to ride about in a carriage with a yellow top, decorated with plumes on the left side, and to call his orders “edicts” in imitation of the Han emperor, all of which was intended to show that he was an equal of the ruler of China".