Free Civil Transportation PE Practice Exam Problem: Stopping Sight Distance
- Andrea R
- Oct 10
- 2 min read
A topic you might encounter on the Civil PE Transportation Exam is stopping sight distance (SSD). It may show up tied to vertical or horizontal alignment design problems.
It's important to solve practice questions related to sight distance, perception–reaction time, and driver braking behavior. Here is one to help you prepare for the Civil Transportation PE exam:
Problem
A two-lane rural highway has a design speed of 50 mph.Assume a perception–reaction time of 2.5 seconds, and a braking deceleration rate of 11.2 ft/s².
What is the required stopping sight distance (SSD) according to AASHTO design policy?
A. 400 ft
B. 425 ft
C. 475 ft
D. 500 ft
Answer: B. 425 ft ✅
Solution
The AASHTO Green Book provides the general formula for stopping sight distance:
Where:
V = 50 mph
t = 2.5 seconds
f = 0.35 (typical design value for level roads)
G = 0 (level grade assumption)
Rounded to the nearest design value → 425 ft
PE Exam Tips
When solving sight distance problems:
Be familiar with where to find the stopping sight distance formula in the AASHTO Green Book. It's important to spend time before the exam learning where to find key formulas in your exam references books. This will save you valuable time on exam day. Less time searching for formulas means more time to work the PE exam questions.
If the problem involves an upgrade or downgrade, adjust G accordingly: use positive G for upgrades and negative G for downgrades.
Keep Practicing
Sight distance questions on exam day can be fast points if you’ve solved practice questions related to this topic prior to exam day.
If you found this problem helpful, grab the free PDF with 10 Civil PE Transportation Practice Problems to sharpen your skills before exam day. Each problem includes clear solutions, formulas, and the AASHTO references you’ll use on the real exam.
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