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1LOW-VOLUME ROADS BMPS:
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Chapter 1
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RURAL, LOW-VOLUME, farm-to-marketaccess roads, roads
connectingcommunities, and roads for logging or miningare
significant parts of any transportation system. Theyare necessary
to serve the public in rural areas, toimprove the flow of goods and
services, to helppromote development, public health and education,
aswell as to aid in land and resource management (Photo1.1). At the
same time,roads and disturbed areascan produce significantamounts
of sediment(Photo 1.2). They can beone of the greatestadverse
impacts on thelocal environment, onwater quality, and onaquatic
life. Roads canproduce significanterosion, cause gullies, havean
impact ongroundwater, wildlife, andvegetation, impact
socialstructure, degrade scenicvalues, waste limitedfunds, and take
useful landout of production(Photo1.3).
The basic objective of this guide is to helpengineers, planners,
environmental specialists, androad managers make good decisions,
protect theenvironment, and build good low-volume roads.Key issues
that should be addressed when planninga road project include
changes or negative impactsto the area that a road can cause which
may besignificant, irreversible, or difficult to mitigate. The
Ideas are a dime a dozen. People who put them into action are
priceless.-A. Einstein
Photo 1.1Photo 1.1Photo 1.1Photo 1.1Photo 1.1 A minimum impact
rural road that is well drained, has a stabledriving surface,
stable slopes, and is satisfactory for the user.
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long-term social, environmental, andfiscal cost effectiveness of
a proposedroad all need to be examined.Environmental analysis is a
principalway to examine all aspects of aproject, maximize its
usefulness, andminimize problems. Emphasis shouldbe placed on the
use of anInterdisciplinary Team approach.Not all adverse impacts of
roads canbe avoided, but many can, and thenegative and positive
impacts of aroad project should be weighed andevaluated.
Roads are necessary, but theymust be constructed andmaintained
in such a way thatnegative environmental impacts arecontrolled or
avoided. A wellplanned, located, designed, andconstructed road will
haveminimum adverse impacts on theenvironment and will be
costeffective in the long term withminimized maintenance and
repair
costs. Controlling erosion andprotecting water quality
areessential to the quality of life, thehealth of the forest and
woodlandecosystems, and to the long-termsustainability of rural
resources.Vegetated areas such as woodlandsand forests play a vital
role in
Photo 1.2Photo 1.2Photo 1.2Photo 1.2Photo 1.2 A poorly drained
road that has a rough driving surface for theusers, it is a source
of sediment, and it is relatively expensive to maintain.
Photo 1.3Photo 1.3Photo 1.3Photo 1.3Photo 1.3 A problematic road
because of roadcut failures. Instabilityproblems cause road user
delays, and high maintenance or repair costs.
producing, purifying, and maintainingclean water. Roads must
protectwater quality and the bioticenvironment that depends on
it.
Best Management Practicesor BMPs are those principals
andengineering design practices that willprotect water quality as
well as thefunction of the road when properlyapplied. The Best
ManagementPractices presented herein are acompilation of ideas and
techniquesthat can be used in road managementto reduce or eliminate
many of thepotential impacts from roadoperations and protect water
quality.They represent good road design andconstruction practices
that are costeffective in the long run by reventingfailures,
eliminating repair needs, andreducing maintenance.
The purpose of this manualis to present recommended practicesfor
low-volume roads. A low-volume road is commonly defined asa road
that has an average daily traffic
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3LOW-VOLUME ROADS BMPS:
(ADT) of less than 400 vehicles perday, and usually has design
speedsless than 80 kph (50 mph). Theinformation in this manual is
applicableto rural roads, and most of theinformation is applicable
to all typesof roads, although high standardroads are not the
emphasis of thismanual. Soil and water quality issuesrelated to
temperature, nutrients,chemical pollution, debris, quantity offlow,
and so on are also beyond thescope of this manual, although
thereare many varied benefits from theapplication of these
practices.
Each topic in this manual containsa problem statement that
presentsconcerns, advantages, and potentialimpacts for that issue.R
E C O M M E N D E DPRACTICES and information on theproper or most
desirable way to plan,locate, design, construct, andmaintain roads
are presented, alongwith drawings and tables. Finally,PRACTICES TO
AVOID are listedto discourage poor and undesirablepractices.
This manual offers the BestManagement Practices associatedwith
many aspects of roadsmanagement. The informationpresented in this
manual shouldbecome an integral part oftransportation planning and
rural roaddesign. Key to its use is the need tohire and retain
good, well-trained,and experienced engineers in roadagencies to
evaluate problems,consider local conditions andresources, and
implement or adaptthese practices as appropriate.
Ideas are a dime a dozen.People who put them into
action are priceless.
The key objectives of
Best Management Practices are designed toaccomplish the
following:
Produce a safe, cost effective, environmentallyfriendly, and
practical road design that issupported by and meets the needs of
the users;
Protect water quality and reduce sediment loadinginto water
bodies;
Avoid conflicts with land use;
Protect sensitive areas and reduceecosystem impacts;
Maintain natural channels, natural stream flow,and maintain
passage for aquatic organisms;
Minimize ground and drainage channeldisturbance;
Control surface water on the road and stabilize theroadbed
driving surface (Photo 1.4);
Control erosion and protect exposed soil areas;
Implement needed slope stabilization measuresand reduce mass
wasting;
Avoid problematic areas; and
Stormproof and extend the useful life of the road.
BEST MANAGEMENTPRACTICES
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Obviously, some significantdifferences exist in roads needs
anddesign details in varying geographicareas. At times, unique
solutionsare needed. Mountainous regionstypically have steep slopes
and coldregion conditions; deserts have littlemoisture to support
vegetativeerosion control measures but havebrief, intense rainfall;
jungles oftenhave poor soils and drainageproblems; high valley
regions havedissected, steep terrain and difficultdrainage
crossings, and so on.However, the basic planning,location, design
and maintenance
concepts, and select BMPs apply toany area. Good planning and
roadlocation are needed in any area.Roadway drainage must
becontrolled and drainage crossingsmust be carefully selected
andproperly designed. All roads needstable slopes, use of good
materials,and appropriately applied erosioncontrol measures. Only
some designdetails vary with specific geographicand climatic
regions. Thus localexperience and knowledge are soimportant in
rural roads.
PPPPPhotohotohotohotohoto 1.4 1.4 1.4 1.4 1.4 A well designed,
minimum impact road that has an appropriate standard for its use,
and astabilized cobblestone driving surface.
These BMPs are applicable toroad construction practices in
mostfield situations. However, BMPsshould be selected (and maybe
modified) for site-specificconditions, with guidancefrom
experienced engineers,managers, or other resourceprofessionals.
They must considerlocal or national regulations.Modifications
should beresearched, designed, anddocumented before being used.They
should be monitored, and theyshould provide for equal or
greaterwater quality protection.
