the average human can walk three miles in one hours.
I find I can would about 1 mile in 20 minutes so that would make it 3 miles in an hour.
"Keep on Truckin"
That is an average speed of 3.75 mph.
The average pace for a human on level ground is 4 miles per hour. So one hour and fifteen minutes.
The average human being can walk approximately 3 miles per hour. If this number was then extrapolated to the period of a day (12 hours) this would equal out to approximately 36 miles walked.
The average human walk speed is about 3.1 miles per hour, so walking 1.8 miles should take about 35 minutes for the average human.
3 miles per hour
Most people walk at a pace of 3 to 3.5 miles per hour (4.82km/hr to 5.63km/hr). 4 miles per hour is considered a brisk walk (6.43km/hr).
It depends on how quickly the human in question puts one foot in front of the other -- factors such as length of stride, weight, and type of terrain effect this. Generally speaking, most people walk at 2.5 to 3 miles per hour. Typically 4 MPH is considered a brisk walk, and at about 6 MPH, you're jogging. Over a long distance (e.g., a marathon) 12 MPH is a world-record pace.
23 miles per hour is approximately the fastest a human has run.
About 1 hour This really depends on how fast you walk. There are people that can run a mile in 4 minutes. I think that the average person walks about 3 - 4 miles an hour. If you walked 1.75 miles per hour then it will take you 1 hour. If you walked at 3.5 miles per hour then it will take you about a half hour. I think an hour for 1.75 miles is rediculous. I say about 35 minutes.
If you walk 2.25 miles in 43 minutes your average speed is 3.14 miles per hour.
If you walk 1.74 miles in 36 minutes your average speed is 2.9 miles per hour.
Given that the average person walks about 3 miles per hour, then it would take them 4 hours to walk 12 miles.