What countries still use miles per hour?

Miles Per Hour: Holdouts in the Metric World

In a globalized era characterized by standardization and metric systems, the measurement of speed remains an exception. While the vast majority of countries have adopted kilometers per hour (km/h) as their official measure, two notable holdouts continue to use miles per hour (mph): the United States and the United Kingdom.

Historical Origins

The origins of mph can be traced back to the British Empire, where it was used for centuries to measure both speed and distance. As the British Empire expanded, so did the use of mph, particularly in its colonies. The United States inherited this measurement system after gaining independence from Britain.

Conversion Challenges

The use of mph in these countries presents challenges when interacting with the rest of the world. International speed limits, aviation regulations, and scientific calculations are all based on km/h. This requires drivers, pilots, and engineers in the US and UK to perform frequent conversions, which can be time-consuming and prone to errors.

Resistance to Change

Despite the practical drawbacks, there has been significant resistance to switching to km/h in the US and UK. In the US, this resistance stems from a combination of tradition, familiarity, and perceived difficulty of conversion. In the UK, there are additional concerns about the impact on road signs and other infrastructure.

Safety Implications

The continued use of mph has potential safety implications. Studies have shown that people tend to underestimate speeds measured in mph compared to km/h. This can lead to overspeeding and an increased risk of accidents. Moreover, the lack of uniformity in speed measurement can create confusion and hazards for travelers crossing borders.

Conclusion

The United States and the United Kingdom remain outliers in the world of speed measurement, clinging to miles per hour while the rest of the globe has standardized on kilometers per hour. While historical factors explain this divergence, the resistance to change presents challenges for international cooperation and poses potential safety risks. As the world becomes increasingly interconnected, it is worth considering the benefits of transitioning to a more universally accepted system of speed measurement.