1 Thinking Inside the BoxPeter Koonce, P.E. City of Portland 1

2 Presentation Outline Call to ActionHighway Capacity Manual Construct for Data Collection In the Loop History 2

3 Traffic Monitoring and Data CollectionWhy We’re Here Today Traffic signals are a big part of the work that we do Need to Improve Management Traffic Monitoring and Data Collection 3

4 HCM Capacity DefinitionTraffic Signal Timing and Operations Capacity Concepts HCM Capacity Definition Capacity, c (lower case) depends fundamentally on the saturation flow rate, s, of the lane Saturation flow rate assumes the maximum rate of flow that can pass through the lane group under prevailing traffic and roadway conditions (expressed in units of vehicles per hour of effective green) green per cycle is g/C: Where g is the green time for a movement and C (capital C) is the cycle length g/c is the effective green per cycle (expressed as a percentage) If we know how many vehicles will discharge from the stop line per lane per unit of time (I.e., the saturation flow rate), and if we also know the amount of time available to discharge traffic from the approach (i.e., the effective green time), then it is easy to calculate the capacity according to the formula shown above. The most accurate way to estimate the true saturation flow rate for any lane group is through field measurement. The equations and procedures which follow are for use when field measurement is impossible or impractical. As an example, suppose the field-observed saturation flow rate for a single-lane lane group is 1,600 mixed vehicles per hour (vph). Suppose also that the effective green time for this movement is observed to be 20 seconds each cycle, and the cycle length is 80 seconds. Then the capacity of this lane group is: (1600 vph) x (20 sec/cycle) / (80 sec/cycle) = 400 vph c = s (g/C) 2.1.3 Kittelson & Associates, Inc.

5 HCM Capacity Analysis Calculationwhere i is the various movement or “phase” 2.1.3

6 Time 1 5 2 3 4 6 7 8 2.1.3 HCM Capacity AnalysisConsidering the control of a signalized intersection over time you can start to consider how much time is associated with each traffic flow 1 5 2 3 4 6 7 8 Time 2.1.3

7 Use of Loops for CountingVehicle Counts from a single long loop or multiple loops in a single lane Vehicle Classification and Speed Vehicle Tracking Loop Diagnostics Source: Reno A&E

8 Translating Data into Information8

9 What would additional data do?Enhanced response to customers Reduced liability Prioritizing our efforts 9

10 What should the information be?Effective performance measures should be applicable to the users, easy to calculate, accurate, and clearly and consistently interpreted 10

11 Sample MOEs from NWS VoyageSignal controllers have the ability to collect information Phase service Y/N Ped service Y/N Average Green 11 11

12 Number of pedestrian callsAssists in signal retiming Helps in knowing potential for a pedestrian resulting in longer side street demand Identifies periods of high demand 12

13 Performance Measures for a PhaseMeasure volume + Measure green time Yields an estimate of capacity Identify where split adjustments are helpful 1.0 0:00 24:00 12:00 Volume/capacity Source: Day, C., E. Smaglik, D.M. Bullock, and J. Sturdevant, ” Cycle Length Performance Measures: Revisiting and Extending Fundamentals,” Paper ID: TRB , in press. 0.0

14 Preemption and Priority ReportsRail Emergency Vehicle Priority Bus Operations Other Modes 14

15 Integration of Detection and ControllerRecent research at Purdue University has linked detector activity with controller information The Purdue Coordination Diagram (PCD) collects arrival time of each vehicle at an intersection information about the phase state (red and green intervals)

16 24-Hour Plot of Intersection Saturation1,2 | 3,4 Virtually no slack Capacity 1 9 2 # 3 > 4 " 6 $ 5 : 7 = 8 ! 5,6 | 3,4 Extra Capacity, opportunity to reduce C Source: Day, C., E. Smaglik, D.M. Bullock, and J. Sturdevant, ” Cycle Length Performance Measures: Revisiting and Extending Fundamentals,” Paper ID: TRB , in press. 16 16

17 Test advanced features Reduce uncertaintyIn the Loop What it is … The inclusion of a specific traffic controller software in a simulation or model. Why Is it Done Improve Accuracy Test advanced features Reduce uncertainty

18 HIL Set-up

19 Example SW Moody/SW Porter Transit/Auto intersectionAnticipation of 24 preemption calls Requirement of lead-in/lead-out phases Uses all 16 signal channels to accommodate the various modes Cars – PM Peak by 2035 LRT & SC – 40 movements by 2035 Bus – PM Peak by 2035 Peds & Bikes PM Peak by 2035 Will be one of the most unique intersections in Portland Mistakes at the design phase will be expensive to fix later Or will cost operating time at the intersection

20 SW Moody/Porter Rail Movements

21 SW Moody/Porter Under Construction

22 SW Moody/Porter Using HIL we were able toTest & refine signaling plans Additional intersection clearance time Checkouts to prevent track fouling Understanding how the intersection will recover Understand the likely operation of the intersection Using VISSIM we modeled the intersection using a COP 2070 controller to understand how the installed equipment will function

23 Questions Thanks for participatingPeter Koonce, P.E. Principal Engineer @pkoonce