Considerations when applying Paramics to Strategic Traffic Models Paramics User Group Meeting October 9 th, 2009 Presented Matthew Juckes

Who We Are Scotland, New Jersey, California offices Consultancy Project Audits/Peer Review / Training Paramics Training given to Caltrans, NYSDOT, NYCDOT, WISDOT and many others British Chamber of Commerce - International Business Award 2009

Introduction Introduction Strategic Model Example – I-405 District 12 Strategic Model Example – I-405 District 12 Study Area Study Area Network Information Network Information OD Matrix Information OD Matrix Information Considerations Considerations Project Scope Project Scope OD Development OD Development Simulation Speed Simulation Speed Software Enhancements Software Enhancements Actuated Signals Actuated Signals Freeway MOE Freeway MOE Ramp Metering Ramp Metering HOV Lanes; and HOV Lanes; and HOT Lanes HOT Lanes Output Statistics Output Statistics Conclusions Conclusions

Study Area  A mile segment of the I-405) from the Los Angeles/Orange County Line to the I-405/ I-5 Interchange.  I-405 traverses an area with several key traffic generators and has freeway to freeway interchanges with the SR-73, SR55, SR-133 and I-5

I-405 – Los Angeles/Orange County Line and I-405/ I-5 Interchange 25.4 Miles AM Period 06:00 – 10:00 (1 hour warm up period) PM Period 15: :00 (1 hour warm up period) 3896 Links 114 Zones 49 Ramp Meters (SATMS) 7 Freeway to Freeway Interchanges (I-605, SR-22 (two times), SR-73, SR-55, SR-133 and I-5 ) Gradients and grade separations Modelled I-405 Base Model Information

PEMS Base Mainline Data

Matrix Totals I-405 AM Trip Matrix – 568,527 vehicles I-405 PM Trip Matrix – 639,594 vehicles

Matrix Development Trip matrices have been developed for all vehicle types. These have been entered in 2 matrix levels corresponding to the Single Occupancy Vehicles (SOV) and the High Occupancy Vehicles (HOV). Trip matrices have been developed for all vehicle types. These have been entered in 2 matrix levels corresponding to the Single Occupancy Vehicles (SOV) and the High Occupancy Vehicles (HOV). A three-stage process has been used to develop the AM and PM peak hour trip matrices for both the SR-22 and I-405 models; A three-stage process has been used to develop the AM and PM peak hour trip matrices for both the SR-22 and I-405 models; The original strategic model (OCTAM Model) was cordoned to produce an AM and PM demand matrices. The original strategic model (OCTAM Model) was cordoned to produce an AM and PM demand matrices. Infill for unobserved trips. Generations were estimated from each zone and distributed to other internal zones; these infill trips were predominantly applied to match the internal turning movements. Infill for unobserved trips. Generations were estimated from each zone and distributed to other internal zones; these infill trips were predominantly applied to match the internal turning movements. The matrices produced at the end of the above steps were then used as the input (pattern) matrices for the Paramics matrix estimation procedure. In essence this ME procedure uses link and turn counts to control changes to the matrix totals and trip distribution. The matrices produced at the end of the above steps were then used as the input (pattern) matrices for the Paramics matrix estimation procedure. In essence this ME procedure uses link and turn counts to control changes to the matrix totals and trip distribution.

What is the aim of the project? Is it to consider mainline operation, arterial operation or both? Is traffic data comprehensive? Is it comprehensive enough to achieve the aims of the project? What are the key routes and intersections? What is the model time period? timescales/deadline – is it possible to deliver the project in the timescales? Large strategic models can be challenging to calibrate. Are the software functionalities suitable/relevant to the project? Project Scope

Default Time Steps - 2 Steps per Second Increasing time steps will increase mean headway; and Increases simulation time (and therefore project costs) Think how many times model is run during Calibration times, 300X30 (min) = 9000min/60 = 150 hours / 8 = 19 days = roughly an extra month of work Simulation Speed

Traffic Signals – Actuated/Fixed Ramp Metering – Fixed/SATMS/TOS/Alinea HOV Lanes – weaving/non weaving; and HOT Lanes What are the potential disbenefits using external software enhancements? Reduced simulation speed Model instability; and Model complexity. Software Enhancements

Fixed Time vs Actuated Signals  Fixed Time Plus – Standard GUI, easy to create; Minus – Does not always match real world conditions;  Actuated Signals Plus – Better match of real world conditions - Greater signal capacity Minus – Requires using VA script or API Can be very time consuming and the final result is almost never perfect

Ramp Metering – Fixed/SATMS/TOS/Alinea  Fixed – Not a perfect situation but quick and easy;  Actuated simple – Simple call detection;  SATMS – Semi Actuated Traffic Metering System Requires API demand-capacity based traffic responsive control or Fixed time  TOS – I-880 – CALTRANS Requires API  Alinea - local feedback ramp-metering strategy Requires API Some concern on the use of Downstream Volumes

HOV Lanes – weaving/non weaving Separated links vs Restrictions with rules/API Depends on goals of the projects and scenarios HOT Lanes Newly available function within paramics Variable Cost Lanes Dynamic link rules

What are the potential impacts to using external software enhancements? Reduced simulation speed; Model instability; Model complexity; Model technical support; Multiple layering effect Miss use of Plugin Over use of Plugins

Modelled Link Counts Example: I-405 AM Northbound Modelled Turning Counts Example: I-405 AM Travel Times Individual vehicle travel times, mean, max and minimum Is a comparison between modelled and surveyed travel times possible? Speedplots – data output, what is being compared. Visuals Example Output Statistics

Macro – Micro Iterations In a perfect world no manual adjustment needed Regional Model (Macro) Sub-Area Macro Model Micro-Model Trip Table Manual Adjustments Final Model Link and Node MOEs Re-Run Macro with Micro MOEs as new input

Link Count Example 131 Turn Counts in I-405 Model >85% GEH 85% GEH < 5.0 for each hour

Turn Count Example 149 Turn Counts in I-405 Model >85% GEH 85% GEH < 5.0 for each hour

Travel Times Individual vehicle travel times, mean, max and minimum Is a comparison between modelled and surveyed travel times possible?

Speedplot Example

Visuals  Screenshots  3D PMX models When is it worth developing a detail 3D background for your model? Google Sketchup – User friendly free PMX designer  Videos – I-880 Example

FHWA Guidelines  Bottlenecks  Counts  Travel Times Does the order that these are validated in really matter? Sometimes something has to give…

For Further Information Richard Braidwood (213) or Matthew Juckes (732)