Regional Bicycle Demand Model:In Use Today in Portland

Bill Stein, Metro

TRB Transportation Applications ConferenceReno, Nevada – May 9, 2011

Presentation overview

• Attributes of Portland’s regional bicycle network• Reasons for and features of our bicycle model• Bicycle utility incorporated into regional model• Bicycle path choice / assignment• Next steps

Central Portland bicycle network

Bicycle boulevards

• Low-volume, low-speed streets optimized for bike travel• Treatments include traffic calming/diversion, signage and

pavement markings, and intersection controls• Through movements for bikes prioritized over other

modes

The problem

• Portland policymakers have great interest in learning what types of projects will increase bicycling.• For most trip purposes, our previous regional

model used only distance as the factor influencing bike mode choice.• A tool was sought for evaluating impacts of future

bike projects on mode share and route choice.

Project support

• Portland State University• 2007 GPS survey of bicyclists’ route choices• Dr. Jennifer Dill

• Development of bicycle route choice model• Dr. John Gliebe, Joe Broach

• PTV America• Software support• Chetan Joshi

Survey participants’ home locations

What our bike model does

• Models bicycle travel on all streets—plus multi-use paths—in the Portland-Vancouver metro area

• Path choice is based on full origin-to-destination consideration (not link-to-link)example: percent of route on bicycle boulevard

• Bicycle utilities feed into regional demand model • Robust bicycle assignments, with multiple display

options• Models 24-hour average weekday bicycle flows

Special considerations

• The model currently runs on “satellite” bicycle networks which took substantial effort to build• The model is only as good as our validation data• Run time is not trivial: millions of paths are

individually analyzed several times• Bicycle-transit interactions are not addressed• Path choices are based on route preferences of

current bicyclists

Bicycle utilities in mode choice equations

• Commute (HBW + College)• Mode-specific constant• Coefficients on distance and land use mix• With bike model: coefficient on bicycle utility

• Non-commute (all other purposes)• Mode-specific constant• Coefficient on distance• With bike model: coefficient on bicycle utility

Variables affecting bicycle utility

• Proportion of route on off-street paths, bike boulevards, bike lanes

• Proportion of route on links with grade > 2%• Turns, traffic signals, stop signs per mile• Traffic volumes of on-street travel and opposing links

at left turns• Bridge bike facility type• Distance• Commute or non-commute trip

Bicycle utility & distance coefficients

Trip Purpose Previous model With bicycle utility

Home-based work -3.115 -1.00

Home-based shop, rec, other -1.804 -0.80

Non-home-based work, non-work -0.8608 -0.40

Home-based college -1.588 -0.40

Trip Purpose Previous model With bicycle utility

All 0.01

• Bicycle utility coefficient

• Bicycle distance coefficient

Bicycle mode choice constants

Trip Purpose Previous model With bicycle utility

Home-based work -5.445 -3.33

Home-based shopping -4.105 -2.58

Home-based recreation -2.605 -0.90

Home-based other -4.194 -2.50

Non-home-based work -4.687 -3.48

Non-home-based non-work -4.488 -3.40

Home-based college 0.086 -2.20

Bicycle model application

• Skim creation • Route search based on impedance function• Returns single, best utility path between zones

• Demand model• Bicycle utility added to mode choice equations

• Assignment• Generates up to nine alternative routes per zone pair

based on path utilities • Optimum paths are determined using a stochastic

assignment process

2007 bicycle productions per square mile

2007 bicycle attractions per square mile

2007 bicycle mean distance (miles)

Trip Purpose Previous model With bicycle utility

Home-based work 3.39 3.33

Home-based shop, rec, other 2.15 2.04

Non-home-based work, non-work 2.06 1.81

Home-based college 4.35 4.47

2007 bicycle mode share

Trip Purpose Previous model With bicycle utility

Home-based work 0.92% 0.93%

Home-based shopping 0.63% 0.62%

Home-based recreation 1.93% 1.92%

Home-based other 0.46% 0.49%

Non-home-based work 0.62% 0.62%

Non-home-based non-work 0.38% 0.38%

Home-based college 2.53% 2.44%

Seven paths generated for my commute

2007 modeled bicycle commute flows

2007 modeled bicycle commute flows westbound on the Hawthorne Bridge

Next steps

• Through mid-summer 2011: further testing of model (validation and sensitivity tests)• Beginning late summer: model will be available

for RTP, MTIP, air quality, and corridor projects• Mode choice parameters will be updated when

2011 household travel survey data are available

Questions?

Bill Stein

Metro

503-797-1855

Bill.Stein@OregonMetro.gov