Going from a single-sex high school (all female) to a single-sex college classroom (all male), Sue McNeil didn't see much of a difference. She doesn't remember any time during her undergraduate work in Australia or her graduate work at Carnegie Mellon University when she felt alienated, or when people implied that civil engineering wasn't an appropriate profession for women. The first woman tenured in the engineering college at Carnegie Mellon University, she finds that her most productive hours of the day happen after 10 p.m., which is lucky for her because her students, two daughters, and husband keep her quite busy the rest of the day.

Civil engineers have always focused on building new structures and facilities like bridges and dams, but I'm interested in what already exists. I want to know what infrastructure is out there, what condition it's in, how fast it will deteriorate, what we can do to fix problems we identify, and how much it will cost. To figure these things out, we use economics and engineering, draw on mathematical and computer tools, and utilize technology to collect condition data.

For example, I am particularly interested in what happens to bridges over time. One of the technological tools we use to explore this question is ground-penetrating radar, which helps us to understand what's occurring underneath the surface of the bridge deck--six to eight inches beneath the road surface we drive on. Chloride ions from the salt we use on roads in the winter migrate to the steel reinforcing bar and cause it to corrode. When the bar corrodes, it expands in volume, pushing out the concrete so that the concrete is no longer attached to the steel reinforcing bar. It "debonds" and causes cracks to propagate at that level, which eventually end up as potholes on the surface. The radar helps to find these problems before they surface, literally, which helps local, state, and federal agencies to forecast when the surface will need serious attention. This process really serves as a planning tool because a planning cycle for surface repairs is typically three to five years.

Once we know what's going on underground, we can determine the best fix: put the equivalent of a band-aid on the superficial problems--patch the actual potholes when they surface; to do a repair with minimal interruption of traffic--close down one lane, remove the top surface or deteriorated concrete, and resurface; or do a major repair and close the entire bridge for an extended period of time, which is often planned five or six years in advance. One reason you always see road repairs going on is because road surfaces are only designed to last ten or fifteen years. The agencies responsible for fixing roads and bridge decks do stagger the repairs, but you simply can't avoid user delay and aggravation costs.

Part of my interest is also in how to get better information fast so that we can make better decisions more quickly. Our research team has developed software that uses neural networks to interpret data and figure out how bad a problem is and how much time we have until it needs to be addressed. The current output from the radar is very crude and difficult for untrained eyes to read, but this computer system could make a big difference.

My interest in engineering started early. I grew up in Australia, and because my father was a mining engineer, I was exposed to engineering and engineers most of my life. Periodically, I had the opportunity to go down into coal mines and actually see the engineering process. I saw how taking coal out of the mine relates to geology, how coal is formed in beds, and how it behaves before it is mined. In an underground coal-mining operation you go in with equipment and take the coal seam out; because of the way coal forms, you end up with a very stable layer of rock as a roof, and you leave supports for the roof in the form of coal pillars. Eventually when you finish mining you take out the supports and let the roof collapse behind you. I found all of this fascinating.

My early interest was strengthened by a high school geography field trip. We visited a laboratory for the local water authority, and I saw scale models of dams, spillways, and water treatment works. I remember thinking, "Wow, this is what engineers do." Even as a child I was fascinated by how you take a large-scale structure and model it.

These exposures prompted an interest in engineering on my part and a tacit expectation on my father's part. My father was always technically oriented, and so we always talked science and math. I remember telling friends in my all-girls high school that I was interested in engineering, and I remember their response: "You can't do that." So I started telling people that I was going to the university to do "something" in math or science. This incident wasn't devastating to me, and it didn't affect my goals or plans. But I remember it.

I was lucky to attend college in Australia in the 1970s because it had a system of traineeships that allowed students to work over the summers and provided tuition and stipend during the school year. I was hired right out of high school in 1973 by the Department of Main Roads (the equivalent of a state department of transportation). I began working the summer before my first year of college. For the first two summers I worked in a drafting office where I was involved in road design. Usually, they'd give me a problem someone else had already tackled and ask how I would lay out the road. I had to look at standards and what was already out there. It was great exposure. I also did culvert design for a bridge made out of a reinforced concrete box. I had to work out how much water would be going through the culvert in order to determine how big to make the bridge. The third summer I worked with the surveyors, and we actually went out in the field and put in the stakes where the new road was going to go. During the fourth summer I worked with the computing people on bridge design. The fifth and final summer was spent on road construction sites. The traineeship provided me with hands-on experience and the opportunity to see a lot of real civil engineers at work on very interesting projects.

I don't remember any time during my undergraduate work in Australia or my graduate work in the United States when I felt alienated, or when people pointed out or implied that civil engineering wasn't an appropriate profession for a woman. I just went from a single-sex high school (all female) to a single-sex college classroom (all male) and didn't see much of a difference. Perhaps I wasn't a threat to anyone because there was only one of me!

I got married in 1976, at the end of my fourth year of a five-year program of undergraduate work, then moved on to graduate school at Carnegie Mellon. My husband John's background is in electrical engineering, but over the years he has moved away from engineering and into management consulting. We have always experienced the "two-career problem," which involves a complex set of trade-offs. My daughter, Sarah, was born in June of 1982, near the end of my graduate work. That was a conscious decision. After I finished my dissertation, we moved to New Jersey because of John's job. I worked as a consultant part-time, and then Emily was born in the summer of 1984. The next year I taught at Princeton part-time. At that point I was starting to get the message that two years out of the academic mainstream was a long time, and so I started looking at academic jobs. I went to MIT for my first academic position and two and a half years later received a phone call suggesting that I might like to apply for a position at Carnegie Mellon. I came to Carnegie Mellon in January 1988 with a three year old and a five year old. I was tenured as a full professor in 1994.

I never really had a role model. My interest in the subject drove me to work toward my Ph.D., and my interest in teaching drew me to academic life. I find teaching a tremendous challenge: figuring out ways to keep students not simply awake but excited about engineering. I enjoy students at different levels for different reasons: seeing the twinkle in the eyes of first-year undergraduates when they finally see the connections among physics, chemistry, math, and engineering; watching graduate students pushing the edge of knowledge and finally discovering their niche; and helping teaching assistants to think through what teaching really means in relation to learning. It's rewarding and very time consuming; I often find little time for other things when I'm teaching. I'm always looking for ways to keep myself fresh and interested when teaching the same material over and over: I search for new examples; I try to create new assignments; I explore new teaching mediums. In 1994 I was awarded the engineering college's Benjamin Teare Teaching Award; it was one of my proudest moments.

Despite my success, I have had and continue to have moments of self-doubt, but somehow I've always managed. I've always focused on what I wanted to do and then done it. Tenure hasn't really changed my life. I still feel an obligation to do all those things I did prior to tenure, plus more. My husband and I recently agreed to serve as copresidents of the PTA at our children's school, something that I believe is important but wouldn't and couldn't have done prior to tenure.

The support network I've had and continue to have is incredible. My parents, my husband, and his parents were supportive not only of a professional daughter/wife/daughter-in-law but also of my interest in earning a Ph.D. in civil engineering. My mother came for the arrival of each child and was enormously supportive. My in-laws spent three months in the States watching my one year old so that I could finish my dissertation because my husband was working out of town in New Jersey. My husband, whose profession gives him much more career flexibility than mine, has moved three times for my job. His support has been vitally important in enabling me to achieve what I have achieved.

It's not easy balancing all the roles and responsibilities I've taken on--researcher, teacher, mentor, committee member, taxicab driver, adoring fan, middle school math tutor--but the flexibility of academic life makes it do-able. For example, I'm able to attend many of the children's functions at their school. Also, I'm lucky because I don't need much sleep. I am a night owl, and often my most productive two hours of the day for me are from 10 p.m. to midnight. I relish that time and use it well. Also, we have hired help when we've needed it--nannies, au pairs, someone to clean the house. These people have been invaluable.

My kids have grown up with the university as an extension of our family life. They have come to university functions and classes with me; they've sat through many lectures. I sometimes worry that seeing me do all that I do might backfire--they might just decide that balancing a career and family is just too much hard work. We talk about it, but not as much as we should.

The first thing to go in my schedule, when something has to give, is time for me--swimming, exercising. Every so often I get frustrated and wonder, "Why am I doing all this?" And then I think, "What else could I do?" I love what I do--engineering and parenting. And I wouldn't want to be doing anything else.

"Journeys of Women in Science and Engineering: No Universal Constants" is available from Temple University Press.