This is a tough point of comparison since any distance covered is completely dependent on the person doing the activity.
Is it possible for a trail runner to cover more distance than a hiker? Absolutely.
Is it possible for a speed hiker to cover more distance than a trail runner? Also, absolutely.
Really, the distance traveled for either activity depends on the duration each activity is performed, and the average speed of the activity.
If both activities are done for the same period of time a trail run would cover more ground due to speed. Since it may not be possible for all runners to take on great distances, however, speed hiking might just be the best way to go further.