Turn Lane Length Calculator
Calculate deceleration, storage, and taper lengths for left and right turn lanes based on AASHTO design standards.
Inputs
mph
veh/hr
sec
%
Results
Total Length (with taper)
412 ft
Decel + Storage280 ft
Deceleration Length218 ft
Storage Length62 ft
Taper Length132 ft
Design Queue3 vehicles
Lane Width11 ft
How to Use This Calculator
- Enter Turn Lane Type, Left Turn, and Right Turn.
- Set Approach Speed, Turning Volume, and Signal Cycle Length.
- Adjust Green Ratio (g/C), Approach Grade as needed.
- Review the Total Length (with taper) (ft) result.
- Use Decel + Storage (ft) and Deceleration Length (ft) to inform your decision.
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