mphIreland
An introduction to the traffic rules and road signs of Ireland. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.
For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.
102. mph
mph means miles per hour and is a unit used to measure speed. It expresses how many miles a vehicle or other moving object would travel in one hour if it maintained the same speed.
For example, a speed of 50 mph means travelling at a rate of 50 miles per hour. One mile per hour is approximately 1.61 km/h, so speeds expressed in mph and km/h have different numerical values.
Wikimedia.org • Greg Gjerdingen • CC BY
What does mph mean?
mph is the abbreviation for miles per hour, a unit used to measure speed.
What does 50 mph mean?
A speed of 50 mph means that, if the speed remained constant, the vehicle would travel 50 miles in one hour.
Is mph the same as km/h?
No. mph measures speed in miles per hour, while km/h measures speed in kilometres per hour. 1 mph is approximately 1.61 km/h.

Traffic rules
Ireland