Dash
Typically used with: Muscle.
In short: book it. Sometimes in life, an all-powerful, monstrous creature looms up before us, and we're forced to turn tail and run to the hills. Other times, a nefarious foe has liberated you of your coin purse and you must pursue. The Dash skill is the weapon of choice for triathlon participants and cowards.
Any natural means of locomotion your character may employ, be it running, climbing, flying, or swimming is valid for Dashing.
Chasing
If you're running from the police, a bear, or an assailant, you've got two or more creatures competing for speed. Each participant in the chase makes a Dash check. The character with the highest result is the fastest. If the chaser has the bigger roll, they overtake the pursued. If the pursued has the bigger roll, they escape and leave their chasers in the dust.
Hurrying
All races in this book start with a Speed of 10, meaning they can cover 10 feet per Action Point in combat. If you want to try and go faster than that, you can roll a Dash check. The result of the check dictates the character's velocity. The higher the result, the shorter the time it will take to finish.
If want to sprint at full speed, using all available energy, as fast as you possibly can, roll a Dash check. The result equals your velocity in feet per second. So a DL 5 is 5 feet per second (3.4 mph, average human walking speed), DL 30 is 30 feet per second (20.5 mph). For perspective, a world record for the 100 meter dash is 34 feet per second). Trying to Dash at full speed for more than a few moments is incredibly draining. Your GM should have you roll a Stamina check to keep going past your limits at that speed.
Long distance running is a different story. If you're running more than a quarter mile, your velocity is half your roll in miles per hour. So a DL 5 is 2.5 miles per hour, DL 30 is 15 miles per hour. (For perspective, a world record for the marathon is 13 mph, and a world record for the mile run is 16 mph).
Humans are much slower at swimming than running, and very, very slow at climbing. We couldn't find any world records for human flight.