# Blog Archives

## Stopping Sight Distance

The stopping sight distance (SSD) is the total distance you travel during the time you (a) react to apply brakes, (b) apply brakes and actually begin to decelerate, and (c) vehicle comes to a stop.

Reaction time from AASHTO ($t_R$) is 2.5 s.

Default deceleration rate from AASHTO is 11.2 $ft/s^2$

The total distance traveled using these values on a straight path is: