preliminary tests of a dynamic user equilibrium model

16th TRB Planning Applications Conference

Preliminary Tests of a Dynamic User Equilibrium Model in the Pikes Peak Region

Mary R. LupaSenior Supervising Planner

Path to Enlightenment: Session M7May 16, 2017


• Investigate a readily available Dynamic User Equilibrium module available from the software supporting the existing 4-step model

• Conduct simple planning level tests to understand the outputs available from the DUE module

• Persuade MPO decision makers to invest in dynamic traffic software and research

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Goal of the DUE Tests at PPACG


• Colorado Springs / 2-county region

• 2015 population of 320,000

• Large active military population

• 786 TAZ

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Pikes Peak Area Council of Governments (PPACG) Region


PPACG DUE Approach• Used a PTV product – VISUM Dynamic User

Equilibrium – runs in version 15 and up• An am peak period trip table was extracted from

the 4-step model• 7:00 am to 10:20 am captured in 10 minute intervals• Traffic flows, queuing and speeds are output• Network tasks – reviewed centroid connectors, adapt

outflow values from a similar application

• 6 hour run time on a dual core Intel(R) Xeon(R) CPUX5647 @ 2.93GHz

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Outline of DUE Tests• Three investigations

• Test A: Regional overview of “hot spots” in the am peak

• Test B: Examine link outflow as a surrogate for signal or intersection improvement in a corridor

• Test C: Land use sensitivity tests (Fort Carson / BRAC)

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Test A: Regional overview of “hot spots”

Capture the entire MPO region in a three hour am peak period by ten minute intervals to verify hot spots. Congested intervals 7:10 to 8:20 am selected.

Capture the entire MPO region in a three hour am peak period by ten minute intervals to verify hot spots. Congested intervals 7:10 to 8:20 am selected.


070000


071000


072000


073000


074000


075000


080000


081000


082000


Test A average am speeds (all non-centroid links)


Test A queues (all non-centroid links)


Summary of Test A• While ten-minute queue and average speed are

new and uncalibrated reporting metrics, they offer PPACG a “way forward”

• Refined time slices (am or other periods) can pinpoint the location and time of congestion

• Consistency of mesoscopic and 4-step V/C reports from the AM peak are looked for and expected

• Visuals engage the public and offer more lifelike captures of congestion


Test B: Link Outflow sensitivity test

Test of link “outflow” – the carrying capacity of the existing link flow – at a given node. Can replicates signal enhancement

Test of link “outflow” – the carrying capacity of the existing link flow – at a given node. Can replicates signal enhancement


Link Location Academy Boulevard near Fort Carson Gate

Fort Carson (US Army)

Study Location


Outflow sensitivity testBase AM Peak DUE Application

2010

Test B1Policy - Signal Priority

Enhancement on congested Expressway near Fort Carson

No Network Changes

Outflow

Before After

0.6754 0.8500

Test B2Policy - Signal Priority

Enhancement on congested Expressway near Fort Carson

No Network Changes

Outflow

Before After

0.6754 0.9500


Speed


Queue


Test C: Land use sensitivity tests

Test land use – increasing or decreasing the flow of traffic to a zone or zones. Replicates land use changes such as a new shopping center, BRAC realignment, or new/enhanced tourist attraction.

Test land use – increasing or decreasing the flow of traffic to a zone or zones. Replicates land use changes such as a new shopping center, BRAC realignment, or new/enhanced tourist attraction.


Land use sensitivity testBase AM Peak DUE Application

2010

Test C1

Policy - BRAC Increases Workers/travelers into and Out of Fort Carson by 1.5 in

the AM Peak

No Network Changes

Outflow

Before After

No changes

No changes

Test C2

Policy - BRAC Increases Workers/travelers into and Out of Fort Carson by 2 in

the AM Peak

No Network Changes

Outflow

Before After

No changes

No changes


Speed


Queue


Diverted trafficTest C1

Test C2


Next Tasks• Complete 2015 4-step model and DUE extension• Integrate node delay within 4-step with DUE link

outflow values• Begin collection of and comparison to observed

data• Work with the MPO to educate decision makers

and citizens on the value of dynamic traffic tools


In conclusion• DUE is a powerful mesoscopic tool available as an

extension of existing software used by the PPACG• Mesoscopic tools are a bridge towards more

detailed DTA models• First cut am peak investigations in Colorado Springs

are promising


Contacts

Mary LupaWSP [email protected]

Maureen Paz de AraujoWilson & [email protected]

Chetan JoshiPTV [email protected]

Ken [email protected]

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preliminary tests of a dynamic user equilibrium model

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