Transcript Planning for Accessibility: Definitions and Measures

Accessibility- vs. MobilityEnhancing Strategies for
Addressing Auto Dependence
Susan Handy
University of California Davis
Figure 1. Vehicle-Kilometers-Traveled per Person
in the U.S.
(1936 - 2000)
18,000
16,000
14,000
12,000
10,000
8,000
6,000
4,000
2,000
2000
1996
1992
1988
1984
1980
1976
1972
1968
1964
1960
1956
1952
1948
1944
1940
1936
-
1998
1995
1992
1989
1986
1983
1980
1977
1974
1971
1968
1965
1962
1959
1956
Millions of Constant 2000 Dollars
Figure 2. Total Capital Outlays for Roads in the U.S.
(1956 - 2000)
$70
$60
$50
$40
$30
$20
$10
$0
Consequences…
Avg. annual hours of congestion delay per
person grew from 11in 1982 to 26 in 1999
at a cost of $77.8 billion.
 36 U.S. regions with 85 million people fail
to meet national standards for ozone.
 Transportation sector contributed 513
million metric tons of CO2 and accounted
for 18% of global oil consumption in 2000.

The policy dilemma…
Should policies focus on accommodating
growing levels of VMT because that’s
apparently what the public wants to do?
 Should policies focus on limiting VMT so
as to reduce environmental and other costs?

The alternatives!
Improvements in vehicle and fuel
technology to reduce environmental impacts
without limiting driving.
 But… that doesn’t solve everything!
 Reduce the need for driving by enhancing
accessibility rather than mobility.
 Planning for Accessibility!

Accessibility, mobility, what’s the
difference?

CAMPO 2025 Regional Transportation
Plan: “The primary goal of the CAMPO
2020 Plan is to provide an acceptable level
of mobility and accessibility for the region’s
residents with the least detrimental effects.”
Accessibility, mobility, what’s the
difference?

CATS 2020 Regional Transportation Plan:
“Provide an integrated and coordinated
transportation system that maximizes
accessibility and includes a variety of
mobility options that serve the needs of
residents and businesses in the region.”
Accessibility, mobility, what’s the
difference?

TEA-21: “Increase the accessibility and
mobility options available to people and for
freight”
Accessibility vs. Mobility
Mobility is the potential for movement
 Accessibility is the potential for interaction

Huh?
Good Mobility

Ability to move around
Poor Mobility

Inability to move around
Good Accessibility

Ability to get what you need
 Choice of destinations
 Choice of modes
Poor Accessibility

Inability to get what you need
 No destination choices
 No mode choices
Accessibility vs. Mobility

Good mobility usually
contributes to good
accessibility, BUT...
 You can have good
accessibility with poor
mobility
 You can have poor
accessibility with good
mobility
The Problem
In most places in the U.S….
 Accessibility is mobility-dependent
 Mobility is car-dependent
 That has implications for…
 Persons who can’t drive
 Quality of life for those
who can

Planning for Mobility
Focus on the means, not the end:
 Maximize movement
 Emphasize vehicle needs
 Implications for communities:
 Encourages sprawl
 Limits choices
 Built into standard
performance measures

Planning for Mobility
+
Planning for
Mobility
Levels of
Congestion
+
+
Ease of
Travel
Amount of
Travel
+
Planning for Accessibility
Focus on the ends, not the means:
 Maximize interaction, satisfaction
 Emphasize person needs
 Implications for communities:
 Encourages alternatives to sprawl
 Expands choices
 Requires new performance
measures

Planning for Accessibility
Planning for
Accessibility
Levels of
Congestion
?
Need for
Travel
Amount of
Travel
?
Strategy Options



Mobility-Enhancing Strategies
 Road building
 ITS
Accessibility-Enhancing Strategies
 Land use strategies
 ICT
Mobility-Limiting Strategies
 Pricing
 Road restrictions
Mobility-Enhancing Philosophy
Metropolitan regions need more highways
and freeways to serve growing populations
 We should respect the desire of the
majority to use their cars
 Adding capacity will reduce congestion
and its impacts

ITS - Intelligent Transportation
Systems

From information and automation…
 Roads
 Cars
 Transit
 Freight
Evidence on New Capacity


Recent studies on “induced travel”:
 UC Berkeley study: 10% increase in capacity
leads to 9% increase in traffic
 Others: 10% increase in capacity leads to 4.7%
to 12.2% increase in traffic
 Noland and Cowart: capacity increases account
for 15% of VMT growth annually
Induced travel offsets improvements in
congestion, air quality, and other impacts
Evidence on ITS




TransGuide reduced accidents by 15% and
emergency response time by 20% in San Antonio
(TxDOT)
Advanced Traveler Information System led to
changes in route, departure time, confidence in
Seattle (Volpe)
Smart Ramp for HOVs and buses saved 8.5 - 19.2
minutes per week per user in Portland (Lall &
Lucas)
Long-term effects not yet clear...
Who supports this strategy?

Road building…
 Departments of
Transportation
 The “road lobby”
 The majority of the
public?
 Most of the politicians?
Who supports this strategy?

ITS…
 Technology believers
 Many of the leading transportation
engineering researchers
 Industry, esp. defense-related industry
 Most of the politicians?
Accessibility-Enhancing
Philosophy – Land Use Strategies

By designing communities more like they
used to be, we can reduce auto dependence
Neighborhoods should include
a commercial center
 Neighborhoods should be
linked by a regional transit
system

Interrelated ideas…
New Urbanism
 Transit-oriented development
 Downtown revitalization
 Smart growth
 Infill development
 Preservation

Evidence on NU, et al.
Higher densities are correlated with lower
average vehicle-miles traveled:
 Higher shares of transit and walking
 Shorter driving trips
 Neighborhood design encourages walking
but doesn’t always reduce driving:
 3.4 miles/month saved in best
case in Austin (Handy)

Who supports this strategy?
Most urban designers
 More and more planners
 Some developers
 A healthy share of the public
 Growing numbers of
politicians

Accessibility-Enhancing
Philosophy – ICT

Information and Communications
Technologies (ICT) provide accessibility
without the need for mobility:
 Telecommuting
 Tele-activities
 “E-commerce”
Evidence on ICT
Telecommuting reduces person-miles
traveled by 75% on telecommuting days but
ability and desire to telecommute is limited
(Mokhtarian, et al.)
 Aggregate impact of telecommuting on
annual VMT is 0.8% or less (Choo, et al.)
 Travel impacts of e-commerce not yet
clear…

Who supports this strategy?
Some industry… mixed on telecommuting,
high on e-commerce
 Most regional transportation planners
 A growing number of interest groups for the
mobility impaired: rural areas, persons with
disabilities
 Everyone…?

Mobility-Limiting Philosophy
Drivers pay significantly less for their trips
than they should:
 Out-of-pocket vs. total cost to individual
 Individual vs. societal costs
 If drivers directly paid the full cost of their
trip, they would choose to drive less
 Correct pricing leads to economically
efficient choices

Pricing Strategies
Ideally...
 Gas tax increases
 Parking charges
 Congestion pricing
Realistically…
 Parking cash-out
 HO/T lanes - “Value
Pricing”
Evidence on Pricing





Gas Price: 10% increase in price could mean 1%
decrease in driving (Schipper)
Parking Fees: 10% increase in fees could mean
1.6% decrease in driving (Shoup)
Congestion Pricing: $0.20 per mile during peak
could mean 6% decrease in driving (Litman)
Parking Cash-Out Programs: Reduced vehicle
trips by up to 27% in LA (Wilson)
HO/T Lanes: $2 bought 20 minute savings in
Houston (TTI)
Who supports this strategy?
Believers in the market, with fixes
 Many of the leading transportation planning
researchers

So to conclude…
Adopt accessibility-enhancing strategies to
provide choices
 Adopt mobility-limiting strategies to
encourage choices that reduce VMT

The BIG question…
Just how much mobility can we rightly
expect and demand?
The growing Response…
Don’t we have a right to the freedom not
to drive, too?