Title: How to Calculate Average Speed for a Two-Part Train Journey: A Detailed Breakdown

When analyzing long-distance train travel, understanding average speed is crucial—especially when journeys include varying speeds over different distances. In this case, a train travels 180 miles at 60 mph, then continues another 120 miles at 80 mph. But what is the train’s overall average speed for the entire 300-mile journey?

Understanding Average Speed

Understanding the Context

Average speed is defined as the total distance traveled divided by the total time taken. It’s not simply the arithmetic mean of the two speeds, because the train spends different amounts of time at each speed. Let’s break down the calculation step by step.

Step 1: Calculate Time for Each Segment

  • First Segment:
    Distance = 180 miles
    Speed = 60 mph
    Time = Distance ÷ Speed = 180 ÷ 60 = 3 hours

  • Second Segment:
    Distance = 120 miles
    Speed = 80 mph
    Time = 120 ÷ 80 = 1.5 hours

Key Insights

Step 2: Calculate Total Distance and Total Time

  • Total Distance = 180 miles + 120 miles = 300 miles
  • Total Time = 3 hours + 1.5 hours = 4.5 hours

Step 3: Compute Average Speed

Average speed = Total Distance ÷ Total Time
Average Speed = 300 ÷ 4.5 ≈ 66.67 mph

Conclusion: The Train’s Average Speed Is Approximately 66.7 mph

Final Thoughts

For a train journey with unequal speeds across segments, always calculate time separately before computing average speed—don’t assume equal time or average speeds. This principle applies across all modes of transportation, offering clearer insights for travelers, engineers, and educators.

Understanding average speed helps in planning better schedules, tracking performance, and enjoying a deeper appreciation of travel dynamics.


Keywords: average speed, train journey, travel calculation, average speed formula, 60 mph to 80 mph train, transportation analysis

Meta Description: Learn how to calculate the average speed of a train that travels 180 miles at 60 mph, then 120 miles at 80 mph. Find the correct average speed in this detailed breakdown.