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Chris Bradshaw discusses an
interesting way to value trips. We thought his ideas were a good starting point for
discussion. This posting was originally from pednet, a pedestrian and bicycle discussion
group. To subscribe, send the message "subscribe pednet" to majordomo@flora.org
There is strong support here for what we here now call the "green transportation
hierarchy" (GTH) in which the modes are priorized: walking, first, followed by
cycling, transit, ridesharing, and finally SOV (single-occupant automobile) rather than
the pervious 'enlightened' approach of _balancing_ the modes. This is now in the Official
Plan of our regional government. I developed the concept in a short 1992 paper that I will
append below.
The "corridor idea" is, at first blush, bad, to the extent that it will
lavish more money on the longest trips. But it will not increase longer trips if the costs
are passed on to the traveler, rather than being subsidized by all.
It provides another advantage for the GTH: it will put the longer, faster trips below
ground, rather than the current situation of increased intimidation and endangerment _of_
those taking short, informal trips _by_ those taking formal medium and long trips on the
surface. But it should be used only for trains, rather than private cars, which are both
inefficient (more mass per traveler) and would stimulate car travel to and from the
entrances to the 'corridors."
Our plundering of the energy supplies of the eons has distorted an iron-law of travel:
the more frequent trips are the shortest, while the longer ones are the least frequent.
Here is a table that juxtaposes the frequency, length, and scale of trips:
Table 1: The Seven-Scale Hierarchy
| SPATIAL SCALE |
TIME SCALE |
AVG. TRIP(m) |
% |
MODE |
| Global |
1 year to a lifetime |
8,000,000 |
1 |
air |
| Nation-State |
1 month to 1 year |
560,000 |
2 |
rail,bus |
| City-Region |
1 week to 1 month |
40,000 |
3 |
bus,car |
| Neighbourhood |
1 day to 1 week |
2,800 |
6 |
walk,bike |
| Street |
1 hour to 1 day |
200 |
12 |
walk |
| Family |
1 minute to 1 hour |
14 |
25 |
walk |
| Individual |
1 second to 1 minute |
1 |
50 |
walk |
This shows that the scale of trips best suited to the automobile, city-region, should
constitute only 3% of all trips (if one counts all trips, which traffic engineers do not),
and trips at this scale could also be made by bus, delivery, or bicycle. And since the car
is expensive and space consuming, it is not even ideal at that scale (Peter Saint James
correctly points out that it was invented for rural living and was adopted first by
urbanites just to get to the city's hinterlands).
And, longer trips should require the complete scalar hierarchy of trip segments, such
that at the ends (and at connecting points), walking and taxi/transit would be used,
rather than with the car where this big machine is actually housed in the buildings,
rather than 'moored' some distance away. [I am a fan of car-sharing which requires the
user to walk a few blocks to get access, and it reduces the financial burden that
orwnership imposes, thus making it practical to use it for just a few trips a month,
consistent with the user profile of the above table).
What is making things so bad is that the street and neighbourhood scales have pretty
much withered under the assault of large-scale retailing and "lifestyles" that
have no place for neighbouring (in fact, people in North America avoid their neighbours in
the name of 'privacy'). Thus trips up to the weekly frequency, which should be made by
foot or bike, are now made by car, and this growth in car use has further loosened ties
between people and increased the level of intimidation of the green-modes beyond what once
existed when vulnerable road-users were both respected and noticed.
--Chris Bradshaw
GREEN TRANSPORTATION HIERARCHY: A GUIDE FOR PERSONAL AND PUBLIC DECISION-MAKING
Prepared for Ottawalk and the Transportation Working Committee of the Ottawa-Carleton
Round-table on the Environment (Greenprint), Jan 1992
by Chris Bradshaw (revised September 1994)
The following factors represent choices in urban transportation. Some choices are more
environmentally friendly than other choices. Each trip can be ranked on the nine factors
below. Individuals should make trip - AND lifestyle - choices - and public authorities
should officially direct its resources - funds, moral suasion, and formal sanctions -
based on informal scoring of the factors. The author recognizes that, although readers
will find the hierarchy to be logical, the effect of applying it will seem radical.
What must be noticed is that the model rejects the concept of the balanced
transportation system, where users are assumed to be free to choose between many options.
This is because choices incorporating factors that are ranked low generally have a
_predatory_ impact on other choices. This is because of the extreme range in the choices
possible. Using the hierarchy presented below, the "highest" trip is that made
by a 90-year-old woman by foot across the street to visit a bed-ridden child. The
"lowest" is a trip by an adult male alone in his "muscle car" to
bother his ex-wife living on the other side of town. Where those two trips intersect, our
present system makes the woman wait for the man, and in winter, will cause the snow to be
piled to make a direct trip impossible for her. It's really no different than if there
were no rules at all; "might makes right", the law of all jungles, should be
easy to conceptualize even to a child or a person with fading mental and physical
capacities. Rather, our civilized settlements should be based on "the more you wield,
the more you yield".
FACTORS ("HIGHEST" AT TOP, "LOWEST" AT BOTTOM):
- Mode Walk Cycle Bus Truck Car
- Energy Source Human-powered Gravity Solar, Wind Hydrogen (Not yet commercially
available) Electric or inertia (e.g. flywheel) to store energy from another source)
Hydrocarbon Nuclear
- Trip Length Short Long
- Trip Speed (danger and wind friction) Slow Fast
- Vehicle Size (weight and profile against the wind) Small Large
- Vehicle Utilization (efficiency) Full Empty
- Trip Segment Access to a property Through movement
- Trip Purpose ("exchange value", synergy, sustainability) To meet people To
reach a special place To move goods To reach work To move information For
recreation/entertainment To save a little money For thrills
- Traveller Young child Disabled Senior Visitor/Newcomer Adolescent Adult
EXAMPLES:
A. In Personal Decision-Making
- Choose shoes and clothing comfortable for walking
- Choose residence close to work and shopping
- Rent a car when needed, rather than buy one; buy a smaller, non-polluting car (if car
ownership is necessary)
- Shop at stores nearby, even if price higher (this will strengthen local businesses which
will be able to reduce prices and increase selection over time)
- Choose fold-up bike which can be taken onto bus and into workplace (rather than be
parked on sidewalk)
B. In Public Decision-making:
- Don't encourage cycling until space for riding and parking is available (otherwise
sidewalks and other pedestrian spaces will be used, discouraging a higher-rated mode:
walking).
- Encourage car-pooling and give favoured treatment to cars with several occupants, but
not if most of those attracted come from transit (or other "higher" modes).
- Require higher safety features on the exterior fronts of cars than on inside (to prevent
injuries to pedestrians and cyclists).
- Provide tax incentives for transit users; disincentive for car drivers.
- Implement "road pricing" to charge user fees based on "green"
priorities.
- Encourage tele-commuting work arrangements (both to reduce trips and to rejuvenate
"local life")
- Encourage and support rationalization in goods-movement industry to reduce mostly-empty
trucks and long distances between stops
- At bus stops, widen sidewalk, not street (i.e., no "bus bays")
- allow buses in centre lanes where the ride is better (road "crowning causes
vehicles in outside lanes to bounce violently at intersections)
- Set higher snow clearance standards for "higher" modes; do the same in street
design.
- Don't ban street parking/stopping during "rush" hour
THE ENVIRONMENTAL BENEFITS OF APPLYING THE "GREEN" TRANSPORTATION HIERARCHY:
A. Physical
- Reduced air pollution and acid rain
- Less Noise in public places and homes
- Reduced urbanization of agricultural and sensitive lands
- Less street dirt and grime
B. Social
- Reduced street crime (more "eyes" on street)
- Increased personal fitness
- Higher quality street life
- Fewer injuries/deaths from "accidents"
- Less loss of time due to congestion
- Less need for poor/seniors to buy/maintain a car
- Children spend less time passively being chauffeured (walking is their natural mode
because they remain active and stay within their known world)
- seniors have more independence; less exposure to "accidents"
C. Economic
- Lower energy costs; less vulnerability to energy interruptions
- Revitalized neighbourhood shopping areas
- Lower costs for health care
- Less lost-time from injuries, stress, congestion
- Lower transportation costs to all
SUMMARY
A trip is a trip. Each trip allows us to reach a location at which we conduct personal
or commercial or cultural business. What is being dealt with above is called environment
but really has to do with _efficiency_: what are the benefits and costs associated with
each trip? Whose costs, whose benefits? The trip with the lowest costs (to the traveller
as well as to others) is the one that is "highest" on the nine scales above.
Transportation in cities should "maximize commerce, minimize commotion".
Ironically, the "lowest" trips are too often the ones with the least
importance or benefits, e.g. driving to the store for cigarettes, while the
"highest" are often the most important, e.g., walking to a bank at lunch to
arrange for a mortgage or strolling and bumping into an old friend on a street corner who
tells you about a "chance of a lifetime". Ironically, the car is used for these
frivolous trips essentially _because_ the trip is unimportant (i.e. we place so much value
on our time that we try to get unimportant trips over with quickly) and because external
costs are not charged to the traveller.
The car-as-cocoon also _insulates_ the driver and passengers from the physical and
social environment immediately outside the vehicle while _intimidating_ other-modes
travellers who prefer to be _part_ of that environment. The mentality of driving is really
the mentality of taking private measures to deal with public problems (and of converting
public space to private uses). The attitude of "I'm all right, Jack" is the
result of using the car to insulate oneself from street crime, from poor street cleaning,
from street noise, from local air pollution, people who live on the street, etc.
As if in recognition of these problems, the car manufacturers, the
"aftermarket" producers, and the economy generally have come to provide a range
of amenities that further insulate and amuse the driver - e.g., smoking, playing the CD,
eating/drinking, and talking on the telephone (all of which increase the chance of causing
a collision). It is as if the car has _become_ a destination. One doesn't have to go
anywhere!
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