To find out how far Justin traveled each hour, you can divide the total distance he drove by the total time he spent driving.
Justin drove 156 miles in 3 hours:
\[ \text{Distance per hour} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{156 \text{ miles}}{3 \text{ hours}} = 52 \text{ miles per hour} \]
So, Justin traveled 52 miles each hour.