Move of last few decades to go metric has been intercepted by TEA 21 removing deadline for state conversion. A few states have reverted back to old ways but others are standing firm accepting what can only be the inevitable.

By Jim Thorne, P.E.

Columnist, Public Works Online

I thought we were going metric. We have been ever so gradually moving in that direction for years. Film in millimeters, soft drinks in liters, and 10K races are a few metric conversions that have worked into our culture. All pharmaceuticals are metric as is the health care industry. The entire U.S. auto industry is now metric. Medicine and science are metric. Most electronics are metric. The liquor industry is metric.

What about public works and the construction industry? A lot has happened in the last decade that has moved us closer to metric units but we are not quite there.

U.S. only industrialized country not on metric

The modern metric system was established by international agreement in 1960 and is today the standard international language for measurement. The United States is the only industrialized country in the world that has not implemented the metric system.

U.S products with measurements that are familiar to the foreign buyer have an economic advantage. Actually the most recent effort to go metric was initiated by the Omnibus Trade and Competitiveness Act of 1988 which established the modern metric system (known as the System International, SI) as the preferred measurement system of measurement in the United States. This Act required that the metric system be used, to the extent feasible, in all federal procurements, grants, and business-related activities by Sept. 30, 1992. The Act noted that world trade is increasingly geared towards the metric system of measurements and industry in the United States is often placed in a competitive disadvantage.

Going to metric not a new idea

Thomas Jefferson was an early advocate for the use of decimal based measures. Use of the metric system as a measurement system in the U.S. was legalized in 1866. All standard U.S. measures were redefined in metric units in 1893. The Metric Conversion Act of 1975, which was amended by the 1988 Omnibus Trade and Competitiveness Act, established the metric system of measurement as the preferred system of weights and measures for United States trade and commerce.

Why should construction go metric

We are part of the global construction market. We may not export bridges or highways, but global competition for construction services and products affects businesses and practices in the United States. In addition to construction products that are traded internationally (structural steel, fasteners, wood products, mechanical, plumbing, etc.) is the export of U.S. architect/engineer/contractor services.

Converting the highway industry to metric system enables consultants, contractors, material suppliers, and equipment manufacturers to compete more readily in the global marketplace.

Conversion steps were taken

The 1988 Act required each federal agency "by a date certain and to the extent economically feasible by the end of fiscal year 1992" to use the metric system in procurement, grants, and other business related activities. An Executive Order dealing with Metric Usage in the Federal Government Programs was issued in 1991 that required every federal agency to transition to the metric system. Schedules for conversion were prepared by federal agencies. All direct federal and federal aid construction contracts were to be in metric units by October 1996.

This big push from the federal government led to billions of dollars in metric construction for federally funded projects. All General Services Administration work is now metric, as is the Army Corps of Engineers, Naval Facilities Engineering Command, State Department, NASA, Federal Bureau of Prisons, National Institutes of Health, National Institute of Standards and Technology, and the Internal Revenue Service.

The highway industry was on track to have all federally funded construction done in metric by Sept. 30, 2000. The state departments of transportation formed metric transition groups and according to the AASHTO Metric Task Force, by 1997, 42 state DOTs were substantially complete in their conversion process. This meant they had converted key tools, such as standard drawings, standard specifications, and manuals to metric and they were developing new projects in metric units. The average expenditure by a state DOT for the metric conversion was about $1.6 million. It was estimated that 75% of the 1999 state administered highway construction program was in metric units.

The AASHTO report also cited no major problems for metric construction. It noted that the learning curve for state and contractor employees was short once they began work on a metric project. The key was to work in metric units without attempting to translate back to inch-pound units.

Construction Metrication Council served as guide

Support and assistance in this conversion process could be found from a number of professional organizations (AASHTO, APWA, ITE, etc.). Notable among those providing guidance is the Construction Metrication Council. The council was created by the National Institute of Building Sciences in 1992 to provide industry-wide, public and private sector support for the metrication of federal construction and to promote the adoption and use of the metric system of measurement. This was all part of an effort to increase the international competitiveness, productivity, and quality of the U.S. construction industry.

For the last several years, the Construction Metrication Council has distributed a very informative newsletter that provides a snapshot of what has been happening with conversion to the metric system. The Council has provided updates on the work underway in all areas of the construction industry to convert to metric units. This has not been a minor task given the broad range of products and practices used in construction.

TEA 21 cancelled FHWA deadline

The Transportation Equity Act for the 21st Century (TEA-21) cancelled the Federal Highway Administration's year 2000 deadline for state implementation of the metric system in the design and construction of federally funded highway projects. This left each State DOT to decide whether to continue with the metric system in their construction programs.

When TEA-21 was passed in 1998, 43 state DOTs were on the road to metrication. The most recent issue of the Construction Metrication newsletter indicates that 16 states remain metric only, and seven states are using dual units. These states represent about half of all federal highway spending.

Federally funded construction amounts to roughly $50 billion annually. About half of this goes to buildings and non-highway civil works while the other half goes to state highway projects. The first half, implemented by the Corps of Engineers, Navy, Air Force and General Services Administration, is predominantly metric.

Metric found in variety of products in public works

The broad public works field includes a variety of metric implications. There are the products purchased for public works construction projects, both in finished and raw form. This includes steel, wood composites, masonry products, street lights, street furniture, pumps, grates, and so on. Many items we think are in inch-pound units are actually sized in metric and converted to inch-pound units. It's that global competition thing.

We not only have to consider the physical products that come in metric units, but there are also the design practices and standards that guide how things get built. Much effort has been expended over the last several years producing design manuals in metric units. What happens to all of this good work if an agency backs away from metric design? And what does that agency use as the current standard and practice?

Current situation confusing

So we have almost half of the state departments of transportation doing highway construction in metric units. How confusing is that for consulting firms and material suppliers that work in multiple states? What about the next generation of design manuals and practices? What about potential errors resulting from utility companies reviewing highway plans for utility conflicts in different states and different units? This current situation seems all too confusing and we will hopefully move quickly to a better arrangement.

Get it over with

It looked like this metric thing was really going to happen. I saw it as one of those things you knew was good for you but did not really want to do—like going to the dentist. In the long run you would be better off going now rather than putting it off until it becomes more painful.

I wished they had converted back in Thomas Jefferson's day. It would be one less thing we would have to deal with now. But I think we should deal with it now. I do not look forward to it, but I think it is better to get it over with and move on.

The state DOTs that have continued in their metric efforts should be commended. They have likely received complaints from design firms, and perhaps staff, wanting to stay with the old way of doing things. The states that have backed away from metrication should reconsider their position. It seems inevitable to me that the highway construction industry will become metric. And the sooner we get the transition over, the better off we will be, and our children (grandchildren?) will appreciate us saving them the task.

About the author: James D. Thorne, P.E., is a civil engineer whose work experience has included transportation planning and engineering as well as serving as director of research for the American Public Works Association during the 1990s. Among the topics that he has researched and written about are: public works management practices, storm water management, utility cuts, highway and utility coordination, geographic information systems, transportation finance, and road maintenance.

Edited by Joyce Everhart

Managing Editor, Public Works Online

jeverhart@vertical.net