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Cutting Roadside Trees
Cutting Roadside Trees



Author(s) Michael Pritchard
Authoring Institution Center for the Study of Ethics in Society at Western Michigan University
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Contributor(s) Michael Pritchard
Year 1992
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Notes Case study originally published in “Teaching Engineering Ethics: A Case Study Approach” by Michael Pritchard. Center for the Study of Ethics in Society, Western Michigan University, 1992.
Publisher National Academy of Engineering, Online Ethics Center
Authoring Institution (obsolete) Center for the Study of Ethics in Society, Western Michigan University
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  • Posted 14 years and 2 months ago

    Whenever one acts, one is acting within a context, and the
    context may make some options preferable to others when, all
    things considered, it would be better to do something else
    completely different. For instance, in European countries many
    roadways have trees right near the road. These were often
    planted, among other reasons, to form a canopy over the road,
    making the road less likely to be covered with snow in the
    winter and more likely to be cooler in the summer. No doubt
    accidents happen there too, but the costs of lawsuits to the
    European equivalent of country road commissions has not been so
    great, for whatever reason, that European countries have felt
    moved to remove trees for safety's sake. Indeed, even on
    heavily travelled roads, the autobahn's of Germany, for
    instance, trees are often planted in the center between the
    double lanes of traffic in order, among other things, to
    prevent traffic lights from shining into the eyes of oncoming

    In addition, though widening roadways is the accepted
    procedure in this country, whenever a road becomes so heavily
    travelled that the incidence of traffic accidents increases, it
    is not necessarily the preferred solution if some things were
    fundamentally different. More public transportation is
    available elsewhere, and that can help alleviate traffic
    congestion, and if Americans were willing to use such
    transportation, and it were cheap and readily available, such a
    solution might help. In addition, one can build other roads to
    help alleviate traffic, another two-lane road taking the place
    of doubling the lanes on an existing road. But such a solution
    often produces new problems--other land being condemned, other
    trees being cut, and so on. In addition, it is probably likely
    that any state or federal aid available is tied to widening
    existing roads--tied, that is, to what is the preferred
    solution in this country--rather than anything innovative.

    So Kevin Clearing's problem is that there are few choices
    available to him given, among other things, the state of the
    law in this country and the likelihood that someone, going
    within the speed limit, will crash, and sue, and win a large
    amount of money from the county. There are enormous
    disincentives to do anything other than widen the road, and
    there may be enormous incentives, in the form of support from
    the state or federal government, to do that. One person cannot
    change an entire system.

    Clearing has been asked to come up with a solution to the
    traffic problem, and he has. He has come up with one that does
    not try to change those features of the situation that seem to
    be causing the difficulties--whatever it is about the drivers
    and the situation that has caused one fatal accident every year
    and numerous other accidents, whatever is causing drivers to
    drive too fast on the road, whatever is causing the increased
    traffic on the road, whatever it is in the system that produces
    huge amounts of money to those who are harmed in accidents and
    successfully sue, and so on.

    No doubt other options are available besides widening the
    road--putting speed bumps in the road to slow the traffic,
    putting guard rails up to keep traffic within the roadway,
    increasing police patrols, and so on. Each of these options has
    its advantages and disadvantages, and perhaps one of them, or
    some combination of them, would succeed in making the road

    The decision is ultimately a decision that must be made by
    the road commission. They pressed Clearing to come up with a
    solution, and they presumably must ask him to come up with some
    alternative: it is not clear, that is, that he can act on his
    own initiative.

    If not, then he must act, if he feels impelled, as a private
    citizen, and he will have to decide whether to bring before the
    road commission other options he thinks might help. Deciding
    that will present some problems, for he might be perceived by
    the road commission as undermining the recommendation he gave
    them and so undermining the commission itself. So he ought to
    ask them how they want him to proceed--if he thinks he can do
    anything further regarding the issue.

    If he can proceed on his own initiative, or if the road
    commission asks him to proceed, he ought to present the reasons
    for the original solution provided--the concerns about a
    lawsuit, and so on--and to present alternatives, with all their
    attendant problems and benefits. Clearing ought to have
    originally provided the reasons for whatever solution he thinks
    is optimal, explaining clearly how he is ranking the various
    values in conflict here, how, that is, he weighs safety against
    the concern for the environment represented by the citizens'
    arguing to save the trees. If he now thinks some other solution
    may be preferable, he ought to present it, with its attendant
    benefits and burdens. His obligation, that is, is to further an
    informed and intelligent dialogue among the interested

    It may be that out of that dialogue some alternative
    solution may emerge. For instance, one easy way to ease the
    problem caused by crashes is to make it harder for motorists to
    hit trees, and one way to do that is not to cut down underbrush
    near the road, as is the preferred option among road
    commissions throughout the country, but to plant bushes that
    will absorb the impact of cars, causing minimal damage to them
    and to their occupants by preventing them from running into
    something, like a tree, that will not give upon impact. The
    road would then look far different from how most American
    roadways look--not cleared verges, with a stand of trees beyond
    the grass or gravel, but densely planted verges, with bushes
    close to the roadway. Whether such a dense population of plant
    life could be maintained in a roadway system that relies so
    heavily upon salt to clean off ice and snow in the winter is
    another issue, but the point is not that such planting is the
    preferred solution, but that making clear the reasons for
    various alternative solutions can do much to initiate an
    intelligent and informed dialogue about what ought to be done,
    about which values ought to be given prominence and which
    solutions are more likely to preserve those values and cause
    the least harm to other values at issue.

  • Posted 14 years and 2 months ago

    I have to confess that I'm biased on this case: I like
    trees, and I would never hire a road engineer named Clearing.
    However I don't exactly see an ethical problem either. There's
    a question of balancing aesthetics and safety, a problem of
    values to which there's evidently no correct answer. Clearing
    is an engineer who evidently favors safety over all other
    values, but this is not the unanimous view of the citizens of
    Verdant County. It is not, it seems to me, unethical to take
    Clearing's position (how can it be unethical to do what you can
    to protect human life?), though it may very well be unwise,
    shortsighted, undemocratic and not for the best for the
    citizens of the county.

    Law suits have been filed, and to a certain extent the
    courts have decided that the trees are not an unreasonable
    hazard with regard to excessively speeding drivers. Evidently
    no law suits have been filed against the VCRC by the victims of
    the five or more other fatal accidents, nor by the victims of
    the many non-fatal accidents, which is some reason to think
    that, at least in the opinion of lawyers practicing law in
    Verdant County, the trees do not represent an unreasonable
    hazard. One expedient might be to wait until the next accident
    and the next law suit, and let the courts decide further
    issues; if the County were to lose a suit on grounds that the
    trees should not be so close to the road, that would perhaps
    settle the question. Since the County would be the defendant,
    they would have to defend their trees in court, and whatever
    arguments they use can then be used later to protect the trees
    should the courts rule in the county's favor.

    There is a factual question which Clearing should clear up,
    namely, to what extent the trees are a safety hazard to drivers
    proceeding lawfully and within the speed limit. If the risk to
    such drivers is small, the case for retaining the trees is
    proportionately greater. There is also the question of future
    road traffic volume as Forest Road becomes more and more a main
    artery. Some degree of volume growth will inevitably mean the
    end of the trees, but acting prematurely would be unfortunate.
    Clearing could also research or devise possible alternative
    solutions, such as non-rigid barriers to deflect cars from the
    trees. The point is that everything ought to be done to protect
    the trees, within reasonable safety limits; but no one can say
    what these are. The emotional arguments of the environmental
    group, who seem ready to sacrifice real lives in order to make
    symbolic gestures, ought not to be taken too seriously, except
    as political posturing.

    There is also the fact that a wide straight road is not
    necessarily safest, since drivers are encouraged to speed, beat
    the lights, etc. This is especially true if there is in-coming
    traffic from unprotected curb cuts, which tends to create hairy
    battles for road space. Furthermore, even drivers like trees,
    as long as they don't themselves crash into them, which they
    think they won't do if they drive safely (here is the factual
    issue Clearing could resolve). But if the traffic on Forest
    Drive continues to increase, widening the road will eventually
    be necessary, in order to avoid traffic congestion if for no
    other reason. Therefore the VCRC ought to begin planning for
    this. Consult with citizens' groups to see what they want. Find
    out if the drivers are willing to assume some risk in order to
    avoid destroying the trees. Assign more police patrols to keeps
    speeds down. Try to design a safer road which preserves natural
    beauty. Be prepared to offer new trees, planted in a safe but
    accessible location, as a trade-off for the ones taken down.
    Trees don't last forever and (as environmental groups tell you
    in other contexts) are renewable resources. So sacrificing all
    other values (safety, speed, convenience in travel) in order to
    preserve specific trees is irrational. The goal is to preserve
    natural beauty and other environmental values over-all, not
    necessarily to preserve specific trees.

  • Posted 14 years and 2 months ago

    Progress on this case can be speeded up by starting with a
    comprehensive overview, to avoid any risk of our accidentally
    failing to 'see the wood for the trees'. But seriously, it is
    helpful to step back from the specifics of the trees and the
    road in this case. Some general points about different kinds of
    risks, and their relation to environmental and other benefits,
    should help to clarify what is at stake in the case. My main
    emphasis will be on the complexities of decision-making in a
    case such as this.

    There is a general concern in the development of social
    policy to achieve an acceptable balance between risks and
    benefits for people. Another way of raising the same or
    equivalent issues is to think of individual rights and freedoms
    (including the right or freedom to do things which may be risky
    or dangerous) as requiring to be balanced against the potential
    harms to oneself or to others produced by the exercise of one's

    In balancing risks against benefits, it is useful to
    distinguish two different kinds or categories of risk. The
    first of these could be called 'inherent risks', and concerns
    actions, situations, devices etc. which are inherently risky or
    dangerous. An extreme example would be a hand grenade which has
    had the pin removed and has been thrown. Such a device is
    inherently dangerous to a very high degree, because it almost
    certainly will quickly explode and devastate everything in its
    vicinity, no matter what anyone tries to do to prevent it.

    A more moderate example of inherent risk is provided by the
    activity of rock climbing. It is generally agreed that rock
    climbing is inherently risky, because no matter how one tries
    to minimize the risks and maximize climber safety (through
    training, stronger ropes, and so on), some significant degree
    of risk still remains. This is shown by the fact that good
    climbers are killed or injured in significant numbers every
    year. The inherent nature of climbing risks has the consequence
    that the only way to avoid the risk of such accidents is not to
    climb at all.

    Now let us look at the other basic category of risks, namely
    non-inherent or contingent risks. The important point about
    this category is that the risk for items falling under it
    depends on other situational or contextual features, so that
    members of this category have no standard level, nor any
    minimum level, of risk associated with them.

    For example, the level of risk associated with driving an
    automobile depends upon indefinitely many other factors, such
    as the age of the car and driver, the speed, the road
    conditions, traffic density, and so on. Also, arguably there is
    no definite minimum level of risk associated with driving, that
    is, no inherent minimum risk associated with driving. (Those
    obsessed with achieving arbitrarily low risk levels could
    choose to drive only very slowly on empty or private roads, for

    The significance of the basic distinction (inherent versus
    contingent risks) for public policy is as follows. With
    inherently risky activities, the risk is a known quantity, or
    at least a lower bound can be set on it, so that the activity
    is at least as risky as that lower bound. (For example, perhaps
    the lower-bound of risk for rock-climbing is something like 1
    accident for each 500 person-days of climbing. Doubtless
    insurance actuaries would have precise figures on this, or at
    least on average risks for each activity.)

    Given that inherent risks have a strength which is a known,
    relatively unchanging quantity, it is relatively
    straightforward to compare and balance them against the
    potential benefits of allowing them to take place. For example,
    NASA undoubtedly has good calculations on how likely it is that
    a space shuttle, or an orbiting satellite, will be involved in
    a collision with a meteorite sufficiently large to seriously
    damage the space vehicle and abort its mission. (Such a risk is
    an inherent one because collisions occur randomly, so it is
    impossible to remove the risk by any alterations to the
    vehicle, environment or other factors.) With a reliable
    estimate of the minimum risk, along with the known potential
    benefits of a flight, it becomes a very routine matter to make
    a rational 'go/no go' decision on whether to allow a given

    Another public policy example would be a decision as to
    whether to make an influenza vaccine available. This is
    inherently risky (at a low level of risk), because an
    irreducible percentage of people will have adverse reactions to
    the vaccine. But again, a positive or negative decision as to
    use can be straightforward because the standard minimum risk
    can easily be compared with the specific potential benefits of
    the treatment.

    On the other hand, risk/benefit comparisons in the case of
    non-inherent, contingent risks have a fundamentally different
    structure. It might be thought that their only difference from
    'inherent risk' cases is that the risk is a variable quantity,
    with the particular amount in a given case depending on the
    specific situations or factors that exist. (For example,
    driving an old car very fast is likely to be much more risky
    than driving a new car slowly.)

    But in addition to the risk being variable, the overall
    decision to be made (about whether to engage in an activity,
    given the benefits and risks involved) is now required to be a
    much more comprehensive, overall decision about a whole set of
    risk/benefit data pairs. Recall that for inherent risks, the
    only decision needed is a yes/no decision based on a single
    risk/benefit pair. But with a contingent risk case, there are
    now many possible risks, depending on various factors (the
    benefits might vary also). These many risks, along with the
    corresponding specific benefits, define many risk/benefit pairs
    which somehow must be evaluated as a group.

    It will help to clarify things further if we re-introduce
    the main example from the current case, namely the risk(s) to
    motorists that they might crash into trees along a 3-mile
    stretch of Forest Drive road. The risks are of course
    associated with motorists driving cars along the road. It has
    already been argued that driving is a contingent risk activity
    (the risk depending on speed, etc.) Let us concentrate on the
    trees themselves as the only relevant benefit.

    Our general question could be expressed as follows: is it
    worthwhile for motorists to risk crashing into the trees, given
    the benefits also provided by the trees? Or, acknowledging that
    the trees are just one additional risk among others associated
    with driving, we might ask: are the additional risks of having
    trees (rather than no trees) fully compensated for by the
    additional benefits of having trees (over not having

    If we assume that no changes to traffic regulations, etc.,
    are to be made, the relevant risk/benefit pairs are defined by
    all socially possible distinct cases of 'a drive' along the
    road (given present conditions). Each is distinguished on the
    risk side by driver factors (age, disabilities, driving record,
    frequency of driving,..), car factors (new/old, brand,
    maintenance quality, speed,..), road factors (maintenance,
    traffic density, time of day,..), and environmental factors
    (weather, immediate environment of road including trees,..). On
    the benefit side, arguably this too is variable, for example
    because very fast trips or night versus day driving make visual
    enjoyment of the trees difficult or impossible.

    Somehow, using this potentially infinite set of risk/benefit
    pairs, some decision must be made about the overall benefits
    and risks of allowing the trees to remain uncut. One might
    consider calculating some sort of average or mean value for the
    risk and benefit, but an overall decision might be dominated by
    just a small group of high-risk cases. (Some unlikely
    situations may be so dangerous that a decision to cut the trees
    is unavoidable.)

    In the current case being considered, the possibility of a
    successful lawsuit if there is an accident is yet another
    complication. This risk is not itself involved in the initial
    set of risk/benefit pairs. Rather, given a decision (based on
    that set) to leave the trees standing, the lawsuit is one of
    the risks associated with that specific decision.

    As if things are not complicated enough already, yet another
    whole dimension of the problem must briefly be considered.
    Since we are dealing with contingent risks, it is very tempting
    to try to 'mould' the overall situation and the factors
    involved so as to make a desired outcome (e.g., leave the trees
    standing) highly likely.

    For example, new traffic regulations lowering the speed
    limit, with automatic radar detection and photography of those
    violating the regulations, could presumably eliminate virtually
    all of the original high-risk cases associated with speeding.
    Or should we use some other method instead? What would be the
    risks and benefits of each? Notice that we now are forced to
    somehow compare (formally speaking) the risks and benefits of
    different risk/benefit sets, in making such a decision.

    It might be objected at this stage that 'molding' factors so
    as to get a desired result amounts to simply ignoring the
    original problem, which is that of which result is socially or
    morally most desirable. I would concede this point, but it
    points us toward even greater complexity.

    It seems that somehow we have to consider all socially
    possible 'moldings' of factors relevant to the situation (each
    with its associated set of risk/benefit pairs), whether the
    overall outcome for each is 'yes, cut' or 'no, don't cut'. Then
    somehow (again), the overall risks and benefits of each set
    have to be evaluated relative to each other, so that a single
    winner (or group of similar winners) can be chosen. Its (their)
    decision outcome, as to whether to cut down the trees or not,
    would finally give us what we have been searching for in this

    In conclusion, it is worth noting that the complexities in
    decision-making we have uncovered in connection with contingent
    risks are particularly common in dealing with environmental
    public policy issues (e.g., building of condominiums versus
    preservation of wetlands). Any situations involving loosely
    related factors and complicated tradeoffs will tend to have at
    least the same degree and kinds of complexity of
    decision-making as those discussed here.

  • Posted 14 years and 2 months ago

    Kevin Clearing, as an engineering manager, is confronted
    with a situation that is typical of many situations in which
    engineering managers find themselves. He is faced with trying
    to find a "right" answer to a problem that has no clear cut
    "right" answer. The approach to such a situation is to list the
    possible options, consider the advantages and disadvantages of
    each option and select what appears, after due consideration,
    to be the best option. (Some engineering ethics courses develop
    a decision making matrix for situations like this. Using a
    matrix, alternatives, selection criteria, and weighting factors
    are used to calculate mathematically what appears to be the
    optimum solution.)

    Kevin clearing appears to have at least three options:

    1. Maintain status quo of the roadway. Reduce the speed
      limit further.

    2. Find an alternate route and eliminate the current

    3. Widen the current roadway at the expense of the 30

    Option #1 does not eliminate the problem because drivers are
    already known to violate the existing speed limit. (The thought
    proposed by the environmental group to sue drivers if they
    don't drive sensibly is an irrational, unenforceable solution
    and should be rejected.) Option #2, while it could be very
    effective, is probably not practical because it would involve a
    heavy expenditure of funds.

    Option #3 seems to be the only workable solution and will
    involve Kevin's convincing the environmental group that the
    safety of users of the road is worth the destruction of the
    trees. To encourage the environmental group to withdraw their
    objection to this option, Kevin should develop a plan to do new
    tree and shrub plantings along the newly widened highway to
    restore its beauty and ecological integrity.

    The citizen environmental group is a special-interest group
    and caution must be exercised in dealing with such a group.
    While special-interest groups frequently accomplish worthwhile
    results, they are also frequently guilty of so polarizing a
    situation that it is difficult to reach a rational decision. In
    this case, it is unfortunate that a logical best solution was
    not worked out without the local media adding to the turmoil of
    the situation.

    The special-interest group must be approached in a spirit of
    compromise, settling differences by mutual concessions and
    reconciling conflicts through adjustments in attitude and

  • Posted 14 years and 2 months ago

    Several interesting ethical considerations are raised in
    this transportation engineering dilemma. The most prominent
    issue is the conflict between local interests and the interests
    of the public at large. Other topics that will be discussed in
    this commentary are: the potential value of effective organized
    public opposition, the role of the engineer in a governmental
    planning agency, and the emerging field of environmental

    Transportation planners know that highways generate a great
    deal of local controversy, perhaps more than any other public
    works projects, with the exception of airports and nuclear
    power plants (Goldstein 1987).

    "Roads are immensely popular with all those who do not live
    near them." (Lucas 1987)

    Forest Drive has become a main traffic conduit. The
    population of Verdant County has grown substantially, and the
    volume of vehicular traffic on the highway has doubled in the
    past ten years. Public safety is threatened by the condition of
    the highway. Thus far, however, fatalities have been limited to
    drivers who were exceeding posted speed limits. The Verdant
    County Road Commission, motivated by concerns for public safety
    and liability, has decided to widen the roadway.

    A local citizens' environmental group opposes widening
    Forest Drive, however, as the quality of the local environment
    will be diminished. The opposition group does not wish to see a
    number of healthy trees sacrificed, especially when the problem
    appears to be driver carelessness.

    Moral theory can be employed to support either side in this
    conflict. Finding a solution entirely acceptable to both sides
    may not be possible, but the next step ought to be a series of
    public hearings in which all considerations are fully

    Objections, aired in appropriate public forums, can be of
    great value in arriving at the best planning solutions (Lucas
    1987). Enlightened planners will not only welcome objections,
    but will assist in making the objections effective. Considering
    opposing points of view nearly always improves the quality of
    reasoned judgment. This process implies open communication and
    free access to relevant information by all parties.

    Communication with the public is a difficult problem for the
    planner or engineer in itself, but the most important questions
    are (Goldstein 1987):

    1. How does a planner handle a situation where his client's
      values are far from his own?

    2. How is the planner to comport himself when engaged on a
      project which may be nationally (or regionally) highly
      beneficial but adversely affects a particular locality?

    3. How is the planner to form and express his judgment in
      matters involving the aggregation of preferences.

    In the public forum, planning experts should go beyond a
    presentation of their recommendations. They should be willing
    to fully discuss all factors considered in reaching their
    conclusions, and should actively listen to informed criticism.
    During the discussions the planner should honestly express
    uncertainties in planning assumptions. The opposition will
    likely raise valid arguments, beyond those already presented.
    In this case, for example, Kevin Clearing will be asked to
    acknowledge that improved roads generate increased traffic, and
    he should be willing to honestly respond to this fact. Public
    hearings have little positive benefit when the opposition
    parties feel they have not been honestly received.

    This raises the topic of the role of the professional
    engineer in a governmental agency. Governmental bodies are
    generally more concerned with those issues that affect large
    segments of the population, and tend to be less concerned with
    local interests that affect few citizens. The ethical planner
    will maintain sufficient independence to ensure that local
    interests are carefully considered. Grave injustices may
    otherwise be imposed on individuals for the benefit of the

    The subject of environmental ethics is also relevant to this
    case. Most planning engineers are aware that their decisions
    are environmental experiments as well as social experiments.
    Their role is as the agents of change. Often the environmental
    effects of planning decisions are irreversible.

    Environmental ethics is a relatively new field of applied
    ethics, at least in Western philosophy (Martin and Schinzinger
    1989). Western philosophers have traditionally held that humans
    alone have intrinsic value, and that the natural environment
    exists for the benefit of humankind. Environmental ethics
    questions whether morality is purely anthropocentric
    (human-centered). The environmental ethic suggests that trees
    (or spotted owls) may also have intrinsic value.

    It should be noted that many environmentalists place the
    interests of humans far above that of objects in the natural
    environment and the interests of animals. Conservation of the
    natural environment and its resources can be justified on the
    basis of concern for future generations of humans who will have
    intrinsic value. This form of environmentalism is
    anthropocentric. Environmental conservationists do not
    necessarily ascribe intrinsic value to the natural

    It is not clear from Tom Richard's statement whether he
    bases his value for the threatened trees on a belief in their
    intrinsic value, or whether he wants to preserve natural beauty
    for future generations. A careful reading of his statement
    suggests the latter. However, it is likely that at least a few
    members of the opposition group will subscribe to the concepts
    of the new environmental moral theory. Kevin Clearing should be
    prepared to consider this viewpoint in the deliberations, which
    are sure to be lively and spirited.

    Suggested Readings:

    1. Goldstein, Alfred 1987. "The Expert and the Public: Local
      Values and National Choice," Business and Professional
      Ethics Journal
      , Rensselaer Polytechnic Institute,
      Troy, NY, Vol. 6, No. 2, pp. 25-50.

    2. Lucas, J. R. 1987. "The Worm and the Juggernaut: Justice
      and the Public Interest," Business and Professional
      Ethics Journal
      , Rensselaer Polytechnic Institute,
      Troy, NY, Vol. 6, No. 2, pp. 51-65.M

    3. Martin, Mike W. and R. Schinzinger 1989. Ethics in
      (2nd edition), McGraw-Hill, Inc., New
      York, NY, pp. 262-278.

Cite this page: "Cutting Roadside Trees" Online Ethics Center for Engineering 6/15/1992 OEC Accessed: Tuesday, October 13, 2020 <>