Section 5164 of the Omnibus Trade and Competitiveness Act of 1988 amended the Metric Conversion Act of 1975 and designated the metric system as the preferred system of weights and measurements for U.S. trade and commerce. The major reasons given for converting to metric are international trade competitiveness and ease of use. Since the United States is part of a global economy, the metrication of its manufacturing sector is viewed as an important factor in remaining competitive in world markets. Critics argue that although manufacturing may convert, there seems to be no compelling reason for converting highway signs. The American Association of State Highway and Transportation Officials (AASHTO) has stated that it is difficult to determine that metrication would yield any substantial benefits to the highway industry. Others argue that the metric system is simpler and, once learned, more efficient than English measurement. Section 5164 establishes a policy that requires each federal agency to use the metric system in its procurements, grants, and other business-related activities to the extent economically feasible by the end of 1992. However, conversion may not be required if it is impractical or if it is likely to cause significant inefficiencies, or loss of markets to U.S. firms. The act requires each federal agency to establish guidelines to carry out the policy. In addition, Executive Order No. 12770, signed in July 1991, requires, among other things, that executive branch departments and agencies formulate a metric transition plan by November 30, 1991. The Department of Transportation (DOT) issued its metric conversion plan in 1990 and established policy and administrative procedures for changing to the metric system. DOT required each of its nine agencies to develop a conversion plan and include specific dates for the changeover to metric. In addition, DOT’s policy guidance requires that if an agency identifies an area in which metric conversion is deemed to be impractical or inefficient, it can make an exception to the law if the exception is supported by an analysis justifying such action. Any requested exception is submitted to the Secretary of Transportation for coordination with the other DOT agencies before approval is given. To date, FHWA has not analyzed any aspects of its proposed metric conversion plan, including converting signs to metric units, to determine if an exception was warranted. Only one of DOT’s modal agencies—the Federal Aviation Administration (FAA) has—requested program exceptions to metric conversion. FHWA established a metric work group in December 1990 to develop a conversion plan and timetable. The work group proposed a 5-year transition plan with complete metric conversion by September 30, 1996. After this date, all construction contracts advertised for bids for federal lands, highways, and federal-aid construction would have to contain only metric measurements. As a result, highway and bridge contractors, engineers, equipment and materials manufacturers and suppliers, and state and local governments will have to perform their work in metric units or will be ineligible for federal dollars for highway construction projects. Target dates were set for several key program elements and activities, including converting highway signs, as shown in table 1. By the end of 1995, full conversion is expected for data collection and reporting systems such as the Highway Performance Monitoring System, which collects state-level data on the condition and performance of highways. Furthermore, 39 state departments of transportation will have converted, to metric units, their manuals and procedures that guide highway construction and maintenance. According to FHWA, most state DOTs will meet FHWA’s target dates for most elements of metric conversion. Although FHWA was moving forward on other aspects of converting its highway program to metric, on June 27, 1994, it issued a Federal Register notice apprising the public that the agency had postponed the September 30, 1996, deadline for highway sign conversion until at least after 1996. FHWA officials said that they would establish revised implementation requirements sometime after 1996 and that sign conversion is still an agency goal. The officials said that postponement was necessary because of recent legislative prohibitions on the use of federal-aid highway funds for this activity and because of negative comments received on FHWA’s August 31, 1993, Federal Register notice. During the last 2 fiscal years, the Congress included provisions in DOT’s appropriations bills that prohibited the use of federal-aid funds for placing metric signs on our nation’s roads. Concerns about the cost of conversion have also led to several other legislative actions. For example, the bill to designate the National Highway System (NHS) introduced in the Senate in February 1995 prohibits DOT from requiring states to convert highway signs to metric. In the last session of the Congress, the House passed an NHS bill that included a similar provision. While an NHS bill has not been introduced in the House in this session, HR 1173 has been introduced to prohibit the expenditure of federal funds for constructing or modifying highway signs that are expressed only in metric units. At least one state—Virginia—also passed a law in 1994 that prohibits the use of state funds for converting highway signs to metric units. Negative responses to FHWA’s August 1993 notice also contributed to the agency’s postponement of the metric signage requirement. Overall, about 85 percent of the respondents (2,288 out of 2,731) were opposed to converting English measurement signs to metric units. Most respondents cited the cost involved in converting, and a majority said that the funds could be better used to repair roads and bridges. Several local officials commented that the conversion was another federal mandate without thought of how it would be locally financed. Furthermore, several states that responded requested special funding and an education/public information program before implementing metric signage. Most states have not taken any action to convert their signs to metric units. However, Alabama and Arizona are planning for full conversion of highway signs to metric units. In addition to changing highway signs, such as speed limit and direction signs, to metric units, the Alabama DOT’s strategy includes changing milepost markers to kilometer posts. The state DOT has recently received approval from FHWA to use federal-aid funds to install kilometer posts as a reference system to be used for the collection of highway data. Since this is a reference system and will not replace the milepost markers, FHWA determined that the use of federal-aid funds for the reference system would not violate the prohibition in the fiscal year 1995 appropriations act. Although FHWA has postponed the requirement for states to convert their highway signs to metric units, it continues to be an agency goal. As such, activities that support sign conversion continue. For example, FHWA is currently converting the Manual on Uniform Traffic Control Devices into dual units—English and metric. This manual provides federal guidance to the states on all aspects of road signs. FHWA detailed three options for converting highway signs in an August 31, 1993, Federal Register notice to obtain public comment. Option 1: Replace highway signs through routine maintenance over 4 to 7 years. Some signs would be in metric and some in English until all signs were replaced. Option 2: Convert all highway signs over a 6-month to 1-year period. Priority roads would be converted quickly while other roads would be phased in over a longer period of time. Option 3: Carry out a two-phase transition with dual metric and English measurement signs posted by October 1996 and move to metric-only signs at some time in the future. Although most respondents opposed conversion, about 15 percent voted for one of DOT’s three options for sign conversion. About 70 percent of the 443 respondents supported option 2, about 27 percent supported option 3, and the remaining 3 percent supported option 1. If FHWA requires conversion and federal funds are available, AASHTO’s position is that at least a 2-year lead time is needed to plan the highway sign conversion. After the 2-year lead time, AASHTO proposes that FHWA select a 6-month period for the quick conversion of all highway signs and milepost markers, which is similar to option 2. Furthermore, AASHTO’s proposal would require that, during this 6-month period, all signs containing English units (distances, speed limits, clearances, weights, etc.) be modified to equivalent metric units. An official of the American Trucking Association—a lobbying organization for the trucking industry—told us that while it does not have an official position on highway sign conversion, there are safety considerations associated with the conversion options. For example, if all signs are not converted during the same time period, as AASHTO suggests, drivers might be confused when they see a speed limit sign in metric units, then one in English units. FHWA officials told us that, in implementing sign conversion, they hope to minimize the driving public’s confusion and safety concerns by suggesting ways that states can call attention to the new metric signs. While no guidelines have been completed, FHWA officials said that one approach they are considering is to put metric units in yellow to differentiate them from the English unit signs drivers are used to. For any option, the American Trucking Association official told us that without a nationwide educational process before the conversion occurs, commercial truck drivers and the general driving public may not be familiar with metric units. This lack of education could result in safety concerns related to speed and also clearance heights on bridges and tunnels. Alabama has begun to convert its highway signs. In a manner similar to FHWA’s option 1, Alabama is replacing highway signs with metric signs through routine maintenance and for other reasons such as construction. However, Alabama plans, unlike option 1, to put an English measure overlay on the signs. Under this approach, the state believes that it will save money because the signs need to be replaced anyway, and since signs and overlays are fabricated in the state’s shop, all the overlays could be made now and would not be affected by the cost of future inflation.