LOS Calculator

About the Role

This position involves analyzing Level of Service (LOS) for various traffic facilities using the Highway Capacity Manual (HCM) 2016 methodology. The role focuses on evaluating signalized intersections, unsignalized intersections, roundabouts, and road segments to determine operational performance and delay metrics.

Responsibilities

• Analyze signalized intersections to calculate control delay (seconds per vehicle) for through movements, left turns, and right turns.
• Assess unsignalized intersections (Two-Way Stop Control, All-Way Stop Control, Yield Control) to determine average delay per vehicle.
• Evaluate roundabouts based on the number of circulating lanes (single, two, or three lanes) to measure average delay per vehicle.
• Analyze road segments by assessing traffic volume, capacity, free flow speed, and volume-to-capacity (V/C) ratio to determine LOS.
• Apply HCM 2016 LOS criteria to classify traffic conditions into categories (A-F) based on delay or V/C ratio.
• Interpret and report LOS results to inform traffic operations, planning, and design decisions.

LOS Criteria

Signalized Intersection LOS (Control Delay in s/veh)

• A: ≤10s
• B: 10-20s
• C: 20-35s
• D: 35-55s
• E: 55-80s
• F: >80s

Unsignalized Intersection LOS (Average Delay in s/veh)

• A: ≤10s
• B: 10-15s
• C: 15-25s
• D: 25-35s
• E: 35-50s
• F: >50s

Roundabout LOS (Average Delay in s/veh)

• A: ≤10s
• B: 10-15s
• C: 15-25s
• D: 25-35s
• E: 35-50s
• F: >50s

Road Segment LOS (V/C Ratio)

• A: ≤0.60
• B: 0.60-0.70
• C: 0.70-0.80
• D: 0.80-0.90
• E: 0.90-1.00
• F: >1.00

Qualifications

• Familiarity with HCM 2016 methodology and LOS analysis for traffic facilities.
• Understanding of traffic operations, delay metrics, and capacity analysis.
• Ability to interpret and apply LOS criteria for signalized intersections, unsignalized intersections, roundabouts, and road segments.

LOS Descriptions

• A: Free flow, minimal delay
• B-C: Stable flow, acceptable delays
• D: Approaching unstable flow
• E: Unstable flow, at capacity
• F: Forced flow, breakdown conditions