Transportation Planning and Modeling
Transportation planning is a field involved with the evaluation, assessment,
design and siting of transportation facilities (generally streets, highways, footpaths,
bike lanes and public transport lines). – Wikipedia, Aug 29, 2010 Image: public domain
Rational Planning Method
– defining goals
and objectives,
– identifying
problems,
– generating
alternatives,
– evaluating
alternatives, and
– developing plans
Image: GNU Free Documentation License
Daniel Schwen, the copyright holder
Des Moines MPO
http://www.dmampo.org/
Planning Options
• Short run
–
–
–
–
TSM
TDM
Access Mgmt.
Congestion Mgmt.
• Long Run
– Construction
– Land use
• Future?
– Pricing
– Technology (ITS, fuels)
Congestion Pricing
•
http://www.streetfilms.org/archives/campaign-for-new-yorks-future-congestion-pricing/
Why we don’t use congestion pricing:
http://planningresearch.blogspot.com/2007/03/m
anville-on-why-we-dont-use-congestion.html
Travel demand modeling
• Evaluating alternatives requires
– Estimated travel demand (trips)
– Estimated trip lengths
– Estimated modal shares
– Estimated travel speeds
– Estimated travel delays
– Estimate air quality, noise and energy impacts
• Need a systematic process
“Four” step model
sometimes omitted
optional
Data collection
• Demographic/Socioeconomic
• Transportation system
• Travel behavior/propensity/desires
– Surveys
Study area/zone slide
Travel Demand Modeling
(Forecasting)
• What is travel “demand”?
• Three factors
– Land use
– Socioeconomics and demographics
– Transportation services
(TTYP name 3
characteristics
of these factors
that affect demand)
Trip Generation
• Determine number of “trip ends”
• Methods
– Cross Classification (tables)
– Rates based on activity units (ITE)
– Regression
Trip Distribution
• Determine origin and destination of trips
• Methods
– Gravity model (Need a good shortest path
algorithm)
– Growth factor models
Find the shortest path from node 1 to all other nodes (from Garber and Hoel)
1
1
2
4
3
10
4
14
6
7
3
11
2
15
Yellow numbers 3 represent link travel times in minutes
8
1
3
1
4
4
1
1
3
2
13
6
3
2
3
2
9
3
4
2
5
2
12
1
4
16
FINAL
1
1
2
4
3
4
9
2
5
6
6
4
9
13
10
6
4
7
7
11
8
7
9
12
8
14
1
0
15
8
16
1
0
http://mitchlanaillustration.blogspot.com
©1995 - 2008, AMERICAN PHYSICAL SOCIETY
APS encourages the redistribution of the materials included in this newspaper
provided that attribution to the source is noted and the materials are not truncated or
changed.
From: Davison E. Soper
Univ of Oregon
Mode Choice (Split)
• Which mode (transit, walk, carpool,drive
alone, …) will be used?
• Methods
– Direct generation
– Trip end models
– Trip interchange models
Traffic Assignment
• Which route will the trips take?
• Methods
– Minimum path (distance or time)
– Capacity restrained
• Need a good shortest path algorithm