A trio of researchers affiliated with several institutions in Singapore, the U.S. and Hong Kong, has conducted a study examining the accident rates of blue versus yellow taxis being driven in Singapore and has found taxis painted yellow have lower accident rates. In their paper published in Proceedings of the National Academy of Sciences, Teck-Hua Ho, Juin Kuan Chong and Xiaoyu Xia describe their study, their results and why they believe there was a difference.