(Photo by Ferdinand Stöhr)
SINGAPORE — If you decide to call a taxi, you may be better off asking for a yellow one to pick you up. A new study finds you’re less likely to be in an accident when riding in an industry-standard yellow cab compared to blue ones.
Researchers at the National University of Singapore looked at 4,175 yellow taxis and 12,525 blue taxis in the country over the course of three full years, hoping to discover if either served as a safer option for passengers.
They also used data from the GPS logs of 3,000 drivers over a shorter three-month period to try to minimize the impact of external variables — such as those relating to driving speed, number of stops, and distance driven.
Lastly, the researchers made efforts to ensure that drivers of blue cabs or yellow cabs didn’t differ significantly in age, educational level, or driving experience.
The study ultimately found that those who manned yellow taxis were 9% less likely to be rear-ended than those who drove blue ones.
“The findings of our study suggest that color visibility should play a major role in determining the colurs used for public transport vehicles. A commercial decision to change all taxis to yellow may save lives and potentially reduce economic losses by millions of dollars,” says Professor Ho Teck Hua of the National University of Singapore, in a university release. “Our results are also noteworthy to smaller taxi companies and to drivers who use their private vehicles as taxis to work for private-hire car services,”
Interestingly, yellow cabs were even less susceptible to being rear-ended at night than during the day. A 19% decrease in accidents was found for yellow cabs driving under nighttime street lighting, as opposed to a 5% decrease during the day.
This finding leads to the authors’ conclusion: the noticeability of a bright yellow taxi cab allows their drivers more reaction time to avoid an accident.
If all blue cabs turned yellow, it was estimated that Singaporean cab companies would save $1.4 million a year.
Further research may look into the effects of cab colors other than blue and yellow, along with how vehicle colors impact safety with ride-sharing services like Uber and Lyft.
The study was published in the journal National Academy of Sciences.
Paper Summary
Methodology
The researchers analyzed two comprehensive datasets from Singapore’s largest taxi company over a 36-month period. The first dataset included aggregate accident records for all taxis, while the second provided detailed information on a random sample of 20% of the company’s drivers, including daily driving records, accident history, and demographic information. The company’s fleet consisted of about 16,700 taxis in a ratio of one yellow to three blue. The researchers calculated normalized accident rates per 1,000 taxis per month to account for the difference in fleet size between yellow and blue taxis.
Results
The study found that yellow taxis had 6.1 fewer accidents per 1,000 taxis per month compared to blue taxis (65.6 vs. 71.7), a statistically significant difference. This difference persisted across various analyses, including examinations of specific accident types and lighting conditions. The researchers also found no significant differences in driving behavior or demographics between yellow and blue taxi drivers, supporting the conclusion that the color itself was responsible for the safety advantage.
Limitations
While comprehensive, the study was limited to one taxi company in Singapore, which may not be fully representative of other urban environments. The research also didn’t account for potential long-term effects if yellow vehicles were to become more common on the roads. Additionally, the study focused on taxis and may not fully capture how color affects accident rates for other types of vehicles.
Discussion and Takeaways
The study provides strong evidence that vehicle color can significantly impact road safety. The findings suggest that simple, low-cost interventions like changing vehicle color could have substantial benefits for public safety and economic savings. The research also highlights the importance of visibility in traffic safety and suggests that transportation planners and policymakers should consider color as a factor in vehicle design and regulation. Future research could explore how these findings apply to other types of vehicles and in different urban environments.
Funding and Disclosures
The study was conducted by researchers from the National University of Singapore, the University of California, Berkeley, and the Chinese University of Hong Kong. The authors declared no conflicts of interest. Specific funding information was not provided in the paper.
