What LOS is acceptable for new highway design?

AASHTO recommends design to LOS B or C in rural areas, LOS C or D in urban areas during design hour. LOS D or E may be acceptable for short segments in heavily developed urban corridors where widening is infeasible.

What is the typical freeway capacity?

HCM 7th Edition basic freeway segment capacity: 1700-2400 pc/hr/ln depending on FFS. At FFS 120 km/h: 2400 pc/hr/ln. At FFS 80 km/h: 1750 pc/hr/ln. Actual capacity lower for trucks and grades.

How is v/c ratio used in intersection analysis?

For signalized intersections: v/c = (volume × PHF) / (capacity × g/C). Critical intersection v/c (Xc) = sum of critical movements v/c. Xc > 1.0 indicates intersection is overcapacity.

Level of Service Calculator

Calculate LOS A-F for basic freeway segments per HCM 7th Edition. FFS (free flow speed), volume-to-capacity ratio v/c. LOS thresholds: A v/c<0.20, B 0.35, C 0.54, D 0.77, E 1.00, F>1.00. Density (pc/km/ln) criteria.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate LOS A-F for basic freeway segments per HCM 7th Edition. FFS (free flow speed), volume-to-capacity ratio v/c. LOS thresholds: A v/c<0.20, B 0.35, C 0.54, D 0.77, E 1.00, F>1.00. Density (pc/km/ln) criteria. Use the level of service result to inform your clinical assessment.

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Frequently Asked Questions

What LOS is acceptable for new highway design?

What is the typical freeway capacity?

How is v/c ratio used in intersection analysis?