How to Become a Transportation Engineer: Steps toward a Dynamic Career in Civil Engineering

Transportation engineering is a branch of civil engineering that deals with aspects of engineering related to the planning, design, maintenance, operations, and analysis of transportation systems. This includes transportation systems such as roads and highways, bus networks and busways, railways, light rail and subways, pedestrian networks, and aviation, among others. It is a dynamic discipline which has evolved and will continue to evolve as transportation networks and technology change over time. Of particular importance for the future is the design and construction of more sustainable transportation networks and infrastructure, and transportation engineers can play an important role in this development. In recent years, the field has seen the development of intelligent transportation systems (ITS) and an evolution in the use of ridesharing platforms, autonomous vehicles, and other technological developments. How does one pursue a successful career in the evolving field of transportation engineering? This blog will discuss the path to licensure and realizing one's career goals in the profession.

This blog covers:

1. Transportation Engineering Begins with Civil Engineering

2. Undergraduate Engineering Programs

3. Obtaining Work Experience

4. Finding the Right Engineering Firm

5. Taking Exams

6. PE Exam

7. Obtaining Licensure

1. Transportation Engineering Begins with Civil Engineering

As transportation engineering is considered a branch of the broader discipline of civil engineering, the typical path toward becoming a transportation engineer begins with enrollment in a civil engineering undergraduate program. Even before college, if a student is interested in the pursuit of engineering as a career path, there are now many high schools across the country that focus on STEM education (STEM being an acronym for science, technology, engineering, and mathematics). In any event, a strong background in these areas of study is helpful in beginning studies in civil engineering.

2. Undergraduate Engineering Programs

Most undergraduate programs in engineering begin with courses in the general sciences and mathematics before beginning courses, which are more specialized towards the specific engineering discipline being pursued-in this case, civil engineering. Within many civil engineering undergraduate programs, there is the opportunity to have a concentration in one or more branches of civil engineering, including transportation engineering. Other branches of civil engineering include structural engineering, geotechnical engineering, water resources engineering (including hydraulics and hydrology), environmental engineering (including wastewater treatment), and construction management. The best way to begin your career in transportation engineering is to take courses offered by your program with a focus on topics in this area of study. These may include courses on highway geometric design, traffic analysis and signal design, transportation infrastructure planning, or other topics in transportation studies. Certainly, attending graduate school allows for the opportunity to take such specialized courses and obtain an advanced degree in transportation engineering, as well as the ability to do research which helps shape the future of the profession. Obtaining such an advanced degree gives an obvious advantage in finding work in this field, but it is also an opportunity to gain the specialized knowledge which one will need to specialize in this branch of civil engineering.

3. Obtaining Work Experience

Whether or not an advanced degree is obtained, it is necessary to gain work experience in an engineering office, typically for at least four years, as a requirement towards gaining licensure as a professional engineer. Even while still in school, it is a good idea to seek out internship opportunities to start gaining work experience, obtain familiarity with the profession, and to begin building a professional network. An additional benefit to working as an intern is that firms often rehire former interns for full time positions after their graduation.

4. Finding the Right Engineering Firm

It is important for emerging transportation engineering professionals to find the right engineering firm for them. There are many factors to consider in choosing a place of employment. Ideally, one should seek out a place of employment where mentorship is taken seriously and there are opportunities to work on project types in which one is interested. It is all too easy to get sidetracked from the pursuit of one's professional goals if one does not seek out the support necessary for career development. It is best to seek out a company which is known for their expertise in transportation engineering and which also has senior engineers willing to provide mentorship and guide your professional development. Many firms have regular employee review meetings, and these are great opportunities to discuss professional goals with your employer.

5. Taking Exams

Along with the work experience requirement (which varies by state), engineers must pass both the Fundamentals of Engineering (FE) exam and the Principles and Practice of Engineering (PE) exam. The FE exam is the first of the two exams to be taken. Among other topics, the Civil FE exam includes questions on transportation engineering, specifically on geometric design, pavement system design, traffic capacity and flow theory, traffic control devices, and transportation planning. It is advised for recent graduates to begin planning their approach to studying for and taking their Civil FE exam within the first couple of years of graduation if possible. This allows for many of the exam topics to still be relatively fresh in one's mind from one's studies so that with study one can reinforce one's knowledge and be well prepared for the exam. Regardless of when one chooses to take the FE exam and the PE exam (and it is never too late), one should take advantage of the many study resources which are now easily available, including online courses, study guide books and e-books, and practice questions and exams.

6. PE Exam

The Civil PE exam is typically taken after completing the necessary years of work experience required by the state in which one is pursuing licensure, though the rules may vary by state. The Civil PE exam is a "breadth and depth" exam meaning that candidates are tested on a breadth portion which tests their broad knowledge of the various areas of civil engineering and a depth portion which is specific to a particular branch of civil engineering. The transportation depth version of the exam covers topics including traffic engineering, horizontal and vertical geometric design, intersection geometry, roadside and cross-section design, signal and traffic control design, geotechnical and pavement, drainage, and alternatives analysis.

7. Obtaining Licensure

Obtaining licensure as a civil engineer is only one step in the process of becoming a successful transportation engineer, albeit an important one. It is important to continue to keep professional development goals in mind and discuss them with your employer regularly. An employer will likely be keen to assist in your professional growth and advancement. It is important for emerging professionals to use their early years in the profession to develop a strong knowledge base. Whether one chooses to pursue a management position or a more technical role in the later years of one's career, this foundation will be invaluable for one's development and future success. It is also beneficial to cultivate one's skills in both written and verbal communication, as well as one's ability to work on teams. Develop a sense of curiosity and seek out opportunities for learning all aspects of the profession, from planning and design to an understanding of construction issues. This will make you valuable as an employee but also establish you as a well-rounded professional. Continuing education is also necessary both to maintain licensure as well as to remain informed of continuing developments in the field. Joining professional societies and attending industry conferences are additional ways to gain industry knowledge and network with other professionals.

Summary

In summary, though there are several steps necessary to becoming a transportation engineer, this should not be a deterrent to those seeking a successful professional career in this area of practice. With careful planning, goal setting, and the thoughtful use of professional development resources, one can put oneself on a trajectory to a long and successful career in this dynamic field.

Don't forget to check out School of PE's FE and PE Civil exam review courses! Our subject-matter expert instructors, comprehensive course content, and innovative learning technology will provide you the building blocks to success!

About the Author: Adam Castelli

Adam Castelli is a licensed architect and engineer currently practicing in the Pittsburgh area. He holds a master's degree in architecture from the University of Massachusetts Amherst and a bachelor's degree in civil engineering from Villanova University.

American Society for Testing and Materials (ASTM) Standards

The American Society for Testing and Materials (ASTM) is an international standards organization focused on developing technical standards for a variety of industrial applications. The organization was founded in 1898 by Charles Dudley, who was a Chemist with the Pennsylvania Railroad. While investigating rail breakage fractures, he noted there were different variations in steel quality and published his research on the subject. This subsequently led to the drafting of initial standards that have grown over the years. ASTM was renamed as ASTM International in 2001 and today has its headquarters located in West Conshohocken, Pennsylvania. ASTM International does not formally enforce its standards, but these practices can be enforced by federal, state, and municipal regulations.

Standardization News is published on the ASTM website and Standard Specifications can be purchased through their website too. Standards are published each year for technical quality subjects such as metals, plastics, petroleum, textiles, paints, construction, energy, environmental, medical, electronics, and Personal Protective Equipment (PPE). There are over 30,000 volunteer members in over 140 countries. I have worked with different ASTM standards for both steel and plastic pipeline in the oil and gas industry. There are generally six (6) types of features that you will see with an ASTM document, including Test Method, Specification, Classification, Practice, Guide, and Terminology. You may also see other sections such as Scope, Reference Documents, Terminology, Significance and Use, Procedure, Report, and Keywords. The Documents are like school lab reports since they can include tabulated data, graphs, preliminary site studies, safety, regulations, equations, units, and material properties as well.

In this blog:

1. Class A: Iron and Steel Materials

2. Class B: Nonferrous Metal Materials

3. Class C: Ceramic, Concrete, and Masonry Materials

4. Class D: Miscellaneous Materials

5. Class E: Miscellaneous Subjects

6. Class F: Materials for Specific Applications

7. Class G: Corrosion, Deterioration, and Degradation of Materials

1. Class A: Iron and Steel Materials

Class A items for ASTM include iron and steel materials. This includes different ferrous attributes such as structure, grades, castings, alloys, and testing for steel products. Steel is a staple of the world economy so the name "ASTM International" certainly fits for worldwide applications. Manufacturers must produce components with quality specifications for ductility, ultimate tensile strength, and percent elongation to ensure they are meeting both regulation and safety requirements. As mentioned earlier, ASTM does not directly enforce their standards, but they naturally must be followed so metallic structures maintain their integrity. ASTM A370 specifically covers mechanical testing for steel products.

2. Class B: Nonferrous Metal Materials

The next ASTM designation is for Class B, nonferrous metal materials. This includes many metals that you would see in the periodic table, such as copper, aluminium, gold, and silver. Steel is widely used, which is probably why ASTM A is exclusively reserved for iron and steel. Remember, steel in its basic form is an alloy of carbon (C) and iron (Fe). There are so many applications and procedures that other metallic materials are separate from steel. Brass (66% Copper, 34% Zinc) is also under the ASTM B umbrella. ASTM B16 is for free-cutting brass rod, bar, and wire, including the chemical composition and Rockwell hardness. Other industry tests such as Rockwell hardness and Charpy impact test help to shape ASTM documents, so you can again see how their standards are naturally enforced in the conception of certain designs and practices.

3. Class C: Ceramic, Concrete, and Masonry Materials

Class C is for ceramic, concrete, and masonry materials. Glass is also included with the ASTM C designation. ASTM C1036 contains information about flat glass for architectural products such as mirrors and laminated glass, so you can see aesthetics also play a role in the development of standards. ASTM C67 and C126 involve testing structural brick and clay tile, including compressive strength. I took a ceramics class in high school; while the focus was mainly on it being an art class, there was science involved with the firing process, bringing clay and glazes to a desired final form. Cracking and explosion can occur if not handled properly. One of my trays was flawed, so I learned that first-hand with fissures occurring in my so-called work of art.

ASTM C387 is a specification for concrete mixtures. Concrete has high compressive strength, but weak ultimate tensile strength. When walking on a concrete sidewalk, you will notice that the concrete blocks do not sink due to their high hardness. Concrete is a composite material of water mixed with cement. There are different variations of concrete with portland cement being the most common cementitious material used worldwide. Ceramics generally have high hardness and low toughness (less resistance to fracturing compared to metals). ASTM C144 has masonry information about gradation for joint sand.

4. Class D: Miscellaneous Materials

ASTM Class D refers to miscellaneous materials, including plastics. ASTM does not seem to have a true classification that is exclusive for plastics, so it falls under the miscellaneous category. As I said before, steel is a staple of the world economy, so that would have precedence. Specification ASTM D3350 is the standard for polyethylene plastics; the cell classification of materials is tested according to primary properties such as density, tensile strength, and slow crack growth resistance. Different compounds are used for the manufacturing of high-density polyethylene (HDPE), and they must undergo testing as the ASTM name implies! There are different forms of connecting plastic pipe and fittings with ASTM D3261 as one example, utilizing butt heat fusion. Other topics in the Miscellaneous Materials category include pH of Water (D1293), Elements in Water (D1976), and Electrical Conductivity and Resistivity of Water (D1125).

5. Class E: Miscellaneous Subjects

ASTM Class E involves miscellaneous subjects. This class seems to include the subject of fire, with topics such as Fire Tests for Building Materials (ASTM E119), Surface Flammability of Materials (ASTM E162), and Optical Density of Smoke (ASTM E662). Surface Burning Characteristics of Building Materials (ASTM E84) are included too, as well as Air Permeance of Building Materials (ASTM E2178). Water also appears to be one of the miscellaneous subjects, with Water Vapor Transmission (ASTM E96) and Water Penetration of Exterior Windows and Doors (ASTM E1105) being classified with the ASTM E designation. In addition to fire and water, ASTM E23 involves the Charpy impact test and antimicrobial screening tests are part of the ASTM E2149 specification.

6. Class F: Materials for Specific Applications

ASTM Class F refers to materials for specific applications. Type F can certainly be specific, as I once came across a Standard for Structural Design of Thermoplastic Chambers (ASTM F2787)! Most companies and manufacturers will have general system and design guidelines, but you do need a specific standard for each application; there is no true universal standard that can fit all applications. I have seen this from different soil lab testing and geotechnical studies. Every application and geographic location can be different, but that is the fun of research. In the oil and gas industry, I have seen Class F standards for Solid Wall HDPE Conduit (ASTM F2160) and Joining HDPE Conduit with Mechanical Couplings (ASTM F2176). ASTM F1668 is about construction procedures for buried plastic pipe, but you can see from earlier that ASTM A would be better suited for steel pipe.

7. Class G: Corrosion, Deterioration, and Degradation of Materials

ASTM Class G refers to corrosion, deterioration, and degradation of materials. Deterioration and degradation are important facets in the field of materials science since you are studying failure theory and predicting material performance in certain conditions. It is imperative for manufacturers and vendors to test their products and identify different tolerance ranges so they can make appropriate recommendations for their product selection. And as an engineer, you must be able to choose the correct equipment for a particular design. If the wrong equipment is ordered, this can lead to lost expenditures as well as lost time and other ramifications if equipment is utilized with the incorrect components.

ASTM G154 evaluates changes in material properties when operating fluorescent UV lamps for non-metallic materials. For ASTM G154, environmental conditions are controlled when testable items are exposed to fluorescent UV light, since you are trying to simulate actual conditions that may occur in a live scenario. Corrosion can occur in metallic materials, but since corrosion is its own entity as electrochemistry, it is separate from ASTM A and ASTM B specifications. For example, ASTM B covers general aluminium specifications, but ASTM G69 is for the corrosion potential of aluminium alloys.

Summary

Engineering is an exciting profession: there are always new things to learn and always new standards that can be developed to better both our industry and society. As the engineering profession is always growing, we will continue to need professionals educating themselves. You should always be studious; not just for passing the Fundamentals of Engineering (FE) and Principles and Practice of Engineering (PE) exams or even for your continuing education hours, but also for personal growth. You can browse different industry magazines and websites for more information, and be sure to check back with School of PE for more blog posts too!

About the Author: Gregory Nicosia

Gregory Nicosia, PE is an engineer who has been practicing in the industry for eight years. His background includes natural gas, utilities, mechanical, and civil engineering. He earned his chemical engineering undergraduate degree at Drexel University (2014) and master's in business administration (MBA) from Penn State Harrisburg (2018). He received his EIT designation in 2014 and PE license in 2018. Mr. Nicosia firmly believes in continuing to grow his skillset to become a more well-rounded engineer and adapt to an ever-changing world.

9 Things You Should Know About Hydraulics: A Hydrology Review

Those taking the PE Civil exam should be familiar with the topics of Hydraulics and Hydrology. These topics are covered on the exam regardless of which depth version of the exam is selected. Aside from the Water Resources and Environmental depth exam, which covers these topics in depth, the other exams cover these topics with six to nine questions. Although at first glance, this may not seem to be a large number of questions, it is actually among the topics of the greatest coverage in the breadth portion of the exam. It is therefore especially important to be familiar with these topics to pass the exam.

The blog covers,

1. Hydraulics

2. Open Channel Flow

3. Closed Conduit Flow

4. Hydrology

5. Storm Characteristics within Hydrology

6. Stormwater Collection and Drainage

7. Runoff Analysis

8. Reading Hydrographs

9. Retention Ponds

1. Hydraulics

The term hydraulics refers to the analysis and engineering of open channel and closed conduit flow systems on the basis of the principles of fluid mechanics. At the level of basic fluid mechanics, it's important to know that the behavior of fluids can be understood by the principles of the conservation of mass, the conservation of energy, and the conservation of momentum. In particular, exam-takers should be familiar with using the Bernoulli equation, which is the equation for the conservation of energy of a fluid. Essentially, it relates the pressure, speed, and height of a fluid at two different points within a changing cross-section of piping.

2. Open Channel Flow

With open channel flow, a fluid is not flowing under pressure within a closed conduit, and its behavior is consequently based primarily upon gravity and the slopes of the channels it flows within. The volumetric flow rate in an open channel is simply the average velocity of the fluid multiplied by the fluid's cross-sectional area. The velocity can be determined with one of two formulas: the Chezy-Manning equation or the Hazen-Williams equation. These formulas, the specifics of which will not be discussed here but with which the exam-taker should be familiar, take into consideration the effects of the friction which occurs between the fluid and the surfaces of the channel through which it flows. It should be noted that the hydraulic radius of a fluid in an open channel is the ratio of the fluid's cross-sectional area to its wetted perimeter (which is that portion of the channel section which is contact with the fluid).

3. Closed Conduit Flow

Closed conduit flow, in contrast to open channel flow, is characterized by a fluid's flow under pressure. Friction losses for closed conduits are calculated using the Darcy-Weisbach equation, which can be used for the laminar or turbulent flow conditions of any fluid, or the Hazen-Williams equation, which can be used for the turbulent flow conditions of water. The Darcy-Weisbach equation utilizes what is known as the Reynolds number as well as the roughness of the pipe to determine the friction loss. The Hazen-Williams equation also factors in the roughness of the pipe, utilizing constant for different pipe materials. Exam-takers should be familiar with these equations for determining friction losses in closed conduits.

4. Hydrology

Hydrology is the study of the distribution and movement of water over and underneath the earth's surface. For the purposes of study for the PE Civil exam, it is necessary to be familiar with storm characteristics, stormwater collection and drainage, runoff analysis, and the use of retention and detention ponds.

5. Storm Characteristics within Hydrology

Storm characteristics in hydrology include storm frequency as well as rainfall measurement and distribution. The concept of rainfall intensity is used in several equations in hydrology. It is the amount of rain in depth over a period of time and can be measured with a rain gauge. Storm frequency can be understood as the likelihood that a storm of particular intensity may occur in any given year. For example, a 20-year storm would have a probability of occurrence of 1/20 in a given year, and a 100-year storm would have a probability of 1/100. Historical data on rainfall intensity and storm frequency is often available on a regional graph of intensity-duration-frequency curves, which can be used to determine the time of concentration for a flow for a particular storm frequency. Time of concentration is the amount of time which it takes for water from the furthest point in a watershed area to reach the point of analysis, and thus it is the time needed for all areas within the watershed area to start contributing to the storm discharge.

6. Stormwater Collection and Drainage

Systems of stormwater collection and drainage include the components of surface drainage such as over street and gutters, culverts, stormwater inlets, and stormwater pipes. The design of the system is intended to provide for the efficient drainage of stormwater and reduce the risk of flooding. Where impervious surfaces carry surface flow, such as along paved areas, streets and gutters, the slopes along with the sectional cross slopes are designed to channel water into stormwater inlets such as catch basins or curb inlets. These collect the surface water into the underground drainpipes which connect to the main stormwater line. Culverts are conduits which allow for the flow of surface water below a roadway or an embankment.

7. Runoff Analysis

Runoff analysis utilizes hydrographs which are based on data from a storm in a particular area. There are different graphical methods which are used to separate the base flow conditions from the additional flow which is a result of a storm event. From this analysis a unit hydrograph can be plotted which isolates the excess flow from the storm event. It plots the discharge (typically in cubic feet per second) over the course of a storm event such that the graphical representation of the data allows for an understanding of a storm's peak flow and it when it occurs. This can be used to help predict the peak discharge for other future storms with different rainfall amounts.

8. Reading Hydrographs

It should be noted that the hydrograph indicates the particular time lag which occurs for peak flows given the particular topography, terrain, and other factors. A significant factor influencing the shape of the hydrograph curve is the amount of development within the catchment area and specifically the permeability of its surfaces. In permeable surfaces, there is a certain amount of time before the ground has reached maximum absorption and the surface begins to carry runoff. In contrast, paved areas will carry the storm water immediately as surface runoff. Thus, the amount of impermeable area within the catchment area will influence the shape of the curve represented in the hydrograph and the peak flow occurring during a storm event.

9. Retention Ponds

Retention ponds are structures which are used to retain water in the event of a storm so that the area's stormwater drainage system is not overwhelmed in the event of a large storm. They can be thought of as being similar to a water body held back by a dam which has a controlled outflow. The water level of the retention pond fluctuates based on precipitation amounts of storm events. Hydrographic analysis can be utilized to determine the necessary size of a retention pond to accommodate a storm of a particular frequency. Unlike retention ponds, which typically have some level of water in them in normal conditions, detention ponds are typically dry except during storm events. Both serve to reduce storm water discharge rates and the risk of flooding. They can also aid in allowing for the settling of suspended sediments, pollutants, and other particles present in the storm runoff, thus aiding in the improvement of water quality.

Conclusion

It is important for takers of the PE Civil exam to understand the basics of both hydraulics and hydrology as these topics are covered on all of the depth versions of the exam. The above summary serves as a short review of basic concepts which should be studied in more detail as these represent the topics for which there may be several questions on the exam.

School of PE's exam review courses provide the resources and tools you need to prepare for and pass your FE and PE exams. Interested in learning more or signing up for a course? Get in touch with us today!

About the Author: Adam Castelli

Adam Castelli is a licensed architect and engineer currently practicing in the Pittsburgh area. He holds a master's degree in architecture from the University of Massachusetts Amherst and a bachelor's degree in civil engineering from Villanova University.

Methods of Estimation in Civil Engineering

The estimation of quantities is an important aspect of civil engineering design projects. Estimates are typically provided to a client in the bid package which is prepared by the design team. It involves not only the estimation of the materials of which the completed project is composed, but also the estimation of the construction labor and equipment which is necessary for the completion of the project work.

 

In this blog,

1. Types of Estimates

2. Approximate or Rough Estimates

3. Detailed Estimates

4. Material Component of Estimation

5. Determining Unit Costs

6. Allowances

7. Non-Material Components

8. Earthwork

1. Types of Estimates

Estimates performed throughout the design process help the project team and owner gain an understanding of project costs and feasibility, keeping the proposed construction within the owner's budget. For this reason, estimates are typically provided at each design submission. Types of estimates include approximate (also known as rough) estimates and detailed estimates. The development of a project typically lends itself to estimation procedures of greater detail and accuracy at the later stages of design.

2. Approximate or Rough Estimates

Schematic level design, for example, lends itself to rough estimates, which can be based on an engineer's previous experience with costs. One might, for example, have a general idea of the typical cost of a parking lot at grade on a square footage basis and apply that number to the particular area which is proposed on a given project. This may not be a very accurate estimate, but it may be good enough to allow the design team to work with a general sense of an item's cost while detail on the design elements has yet to be determined. Given the uncertainties of a design during the early stages of development, design contingencies are typically added to early estimates to reduce the risk of going over the construction budget in the project design at a later stage. This is often provided as a percentage increase in the overall project cost. As the design progresses, the amount of design contingency may be lowered since there is typically less uncertainty about the design as a project progresses.

3. Detailed Estimates

Detailed estimates break down design items into their various components to gain greater accuracy of estimation. This includes separate cost components of material, labor, and equipment. For this reason, detailed cost estimation is sometimes referred to as the unit cost method. The use of unit prices and the components of an estimate which apply to them are discussed below.

4. Material Component of Estimation

The material component of the estimation is often referred to as a "take-off," as it involves the calculation of material quantities based on plans, sections, elevations, or other design drawings. The calculations for an estimation depend upon the typical unit of measure which is used for the material being estimated. This could be based on volume, area, length, unit count, or overall weight, depending on the material. The cost component of an estimation is determined by multiplying the material quantity by the corresponding unit cost to determine the overall cost for the material. For example, a calculated volume of soil in cubic yards would be multiplied by a unit cost defined as cost per cubic yard. Likewise, a calculated number of doors on a project would be multiplied by unit cost defined as a cost per unit to determine the overall cost for the doors on a project. Units of measure for typical items include: units for items such as doors, windows, drains, catch basins, manholes, and plumbing fixtures; feet or meters of length for items such as pipes, guide rails, and striping; square feet or square meters of area for items such as clearing and grubbing, paint, and flooring; cubic yards or cubic meters of volume for items such as concrete, aggregates, earthwork excavation, soil, and backfill; and tons of weight for items such as structural steel and reinforcement.

5. Determining Unit Costs

Unit costs are typically determined from industry estimating databases. Web-based services can provide the most accurate and up-to-date information. Books with published values are also utilized, though less frequently than in the past. Unit costs change over time and location due to factors such as supply and demand, inflation, and labor availability. The databases utilize recent historical data to determine a value for use in estimates. It should be noted that an estimator should review the values found in the databases and evaluate their appropriateness for the project under consideration, as the specifics of the project may warrant an adjustment to the values to gain greater accuracy in the estimate.

6. Allowances

Some items may be indicated in an estimate with an allowance rather than a unit cost basis. The allowance, however, is typically determined based on some type of assumption as to the amount of material or work required, though a precise amount may be unknown whether because of uncertainties in the design or for a lack of sufficient detail in the current stage of design.

7. Non-Material Components

Non-material components of work such as labor typically have a unit of measure in overall labor hours. Multiplication of the labor rate by the anticipate labor hours yields the labor cost. It should be noted that off hours or overtime work may need to be considered as this will increase the unit cost for the labor.

8. Earthwork

Civil engineers should be familiar with the common methods of earthwork calculations related to grading work. Earthwork consists of both cutting and filling operations. The methods of estimation for these include the average method, the block (or grid) method, and the section method, among others. Each may be most appropriate for a given type of project or stage of design.

• Average Method: In the average method, one would first determine the average level of existing conditions, then the average level of the final proposed conditions, and finally multiply this difference by the area of the work. This would roughly determine the overall amount of fill or excavated soil that would be necessary to transport to or from the site. It would be most appropriate to use this method as either a preliminary estimation method or on a smaller scale project.
• Block or Grid Method: In the block (or grid) method, one would divide an area up into smaller areas and determine the amount of difference between the existing and finish grade in each of those areas. One would then multiply the area of each of these blocks by the difference determined from each of these blocks and the sum of these numbers to determine the total amount of cutting or filling. The difference between the two totals would indicate the total soil either required to be brought in or removed. This method would result in more accuracy than the average method.
• Section Method: The section method is most appropriate for infrastructural projects, such as new highways where there is a linear area under consideration. Sections are taken at regular intervals along a path through the project area, such as at the centerline of a roadway. The existing terrain and the proposed terrain shown within these sections allow for the area difference between the two to be calculated using calculation techniques such as the trapezoidal method, wherein complex shaped sectional areas are determined by first breaking them down into simpler areas. These areas would then be multiplied by the distance between the sections taken along the path to determine the volumes of cutting or filling. Computer software is often used to generate these sections once survey data of the terrain is imported into the software.
• Soil Swell: It should also be noted that a given volume of soil, once excavated, typically expands to a larger volume, and this should be taken into consideration when determining the number of vehicle trips required for transporting the soil. This is sometimes referred to as "swell." When soil is brought into a site and then compacted, it occupies a smaller volume of space. This is sometimes referred to as "shrinkage."

Conclusion

In summary, understanding how to do quantity take-offs and determining estimated costs is a key task in civil engineering. In order to develop the most accurate cost estimates, civil engineers should be familiar with the various types of estimates and how they are made. They should also be familiar with the particular methods for estimating common work items in civil engineering such as for earthwork. Accurate quantity and cost estimates are essential for successful projects that are delivered within budget.

Are you figuring out which direction you want to take in life? If you are interested in engineering, School of PE has a comprehensive exam review course to help start you down the path to success! Register today!

About the Author: Adam Castelli

Adam Castelli is a licensed architect and engineer currently practicing in the Pittsburgh area. He holds a master's degree in architecture from the University of Massachusetts Amherst and a bachelor's degree in civil engineering from Villanova University.