Transcript Presentation - 15th TRB National Transportation Planning

Regional Bicycle Demand Model:
In Use Today in Portland
Bill Stein, Metro
TRB Transportation Applications Conference
Reno, 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
• Bicycle utility coefficient
Trip Purpose
Previous model
All
With bicycle utility
0.01
• Bicycle distance coefficient
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
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
[email protected]