Traffic Flow Parameters Surface Street Application

Traffic Flow Parameters Roadway performance Measures –Level of Service (LOS): Measure of congestion of a roadway facility in terms of delay –Levels A through F –Compares vehicle demand to street capacity –Shortcomings: Does not measure person trips or individual mobility

Traffic Flow Parameters What affects Level of Service –Vehicle speeds –Vehicle types (cars, large trucks, SUVs) –Street Network (intersection spacing, etc) –Traffic Signal Coordination & Timing –“Friction” (driveways, street parking, accidents, narrow lanes)

Level of Service

A: Free flow B: Stable flow C: restricted maneuverability D: Instability E: At capacity F: Stop-and-go Levels of Service

Burbank LOS Measurement

Traffic Flow Hourly Travel Characteristics

Reoccurring Congestion

Street Capacity Limitations Building New Street Capacity –Limited opportunities for Street Reconstruction –Most widening is at Intersections –Fiscally expensive, disruptive to sidewalks and adjoining land uses –Increasing capacity can increase demand for new vehicle trips (Induced Demand)

Traffic Flow Improvements Increase Operational Efficiency –Traffic Signal Coordination & Synchronization –Minor roadway re-striping (add turn lanes) –Remove Parking (peak period, near intersections) –Consolidate Driveways and Access Points –Left Turn Phasing

Traffic Flow Improvements Intelligent Transportation Systems (ITS) –Dynamic Traffic Signal Control Plans –Real-time Monitoring –Incident Management –Coordination & Communication with Others –Traffic Management Center