Migrating from Reactive to Proactive Traffic Management 2012 ITS Virginia Annual Conference Brian Keeler

Agenda  History of Traffic Management Approaches  More Recent Approaches  Traffic Density vs. Speed / Volume / Occupancy Algorithms  Hybrid Strategy for Multi Segment Traffic Management  Examples: Miami and Los Angeles Express Lanes  Summary

Historical Approaches  Existing Tools  Traffic Signals  Time of Day / Queue / Volume Based  Ramp Metering  Reversible Roadways  Tolled Roadways (Barrier, O/D Ticket)  Common Threads  Speed  Volume  Occupancy

State of the Practice  Dynamic Pricing / Managed Lanes  Time of Day  Speed Based  Variable Speed Management  Statistical / Heuristic Modelling  Current  Forecasted

Speed/Volume/Occupancy – Living in the Past The Average Speed You Are Looking at Already Happened!  Speed is a lagging statistic  Volume only tells part of the story  Occupancy is a point source statistic

Traffic Density is More Forward Looking Shows the Convergence of Speed/Volume/Occupancy Data in a Meaningful Way  Simple extrapolation yields a view of the near term future  Allows for modifications in advance of system breakdown  Allows tuning of the system to maintain expected / desired performance  Allows for a corridor-wide tuning The look ahead is important!

You Understand Your Network – Use that Insight  The Data you are looking at contributes to what you will see down the road and in the future  Down Stream Events Effect Throughput  Variable Decision Statistics  Component Strategies  Time of Day / Day of Week / Weather  Sensors  Strategically located

Complexity is Evolving As Information Becomes More Reliable & Actionable  95 Express (Miami)  One segment in each direction  Time of Day / Directional based  Focuses on actual segment  LA ExpressLanes (Los Angeles)  Multiple segments each direction  Not as pronounced  Focuses on virtual segments Metro ExpressLanes I-105 $0.75 Adams Blvd $2.70 Metro ExpressLanes I-105 $2.20 Adams Blvd $9.95 Metro ExpressLanes I-105 $3.05 Adams Blvd $12.40

Summary  Your historical perspective and data is valuable  Much work is needed to make these tools truly predictable  The changing/evolving sensor environment dictates a flexible approach to decision tools Brian Keeler