SLEDsmart! USA Knowledge Base

In order to determine a safe speed, you should consider the following factors, including:

• Your reaction time and distance
• The type of terrain
• Your sight distance

What is sight distance?

Good question. Sight distance is the distance at which you can spot an obstacle on the trail and identify it as a hazard.

Reaction Time and Distance

Your ‘reaction time’ is the amount of time it takes you to:

• Spot an obstacle on the trail, and identify if that obstacle is a hazard or not
• React to the hazard by determining if you should brake, or travel around the hazard 

Reaction Distance

Your ‘reaction distance’ is the distance traveled during your reaction time. This is calculated based on your reaction time (in seconds) and your speed (in feet per second) - (reaction time x speed = reaction distance).

To determine feet per second (fps), multiply miles per hour (mph) by 1.46667.

• 15 mph = 22 fps
• 20 mph = 29 fps
• 25 mph = 37 fps
• 30 mph = 44 fps

At 20 mph, using a reaction time of 3 seconds, the reaction distance is: 3 seconds x 29 fps = 87 feet.

This is actually a huge amount of distance traveled. Always take into consideration your reaction distance when determining your speed.