United States General Accounting Office

GAO Report to the Honorable

John J. Duncan, Jr.,

House of Representatives

July 1995 HIGHWAY SIGNS

Conversion to Metric

Units Could Be Costly

GAO/RCED-95-156

GAO United States

General Accounting Office

Washington, D.C. 20548

Resources, Community, and

Economic Development Division

B-260979 

July 7, 1995

The Honorable John J. Duncan, Jr.

House of Representatives

Dear Mr. Duncan:

The Metric Conversion Act, as amended, requires every federal agency to

use the metric system in its procurement, grants, and other

business-related activities to the extent economically feasible. Responding

to the act, the Federal Highway Administration (FHWA) developed a metric

conversion plan and timetable, which included the conversion to metric

units of highway signs, such as, speed limit, distance, and clearance, on all

of the nation’s roads by September 30, 1996. In response to your request,

we have (1) determined the status of federal and states’ efforts to convert

highway signs to metric units and (2) examined the possible costs involved

in implementing the conversion.

Results in Brief On June 27, 1994, FHWA notified the public through a Federal Register

notice that the agency had postponed the September 30, 1996, deadline for

converting highway signs to metric units until at least after 1996. As a

result, most states have deferred their sign conversion activities. FHWA

officials told us that converting the signs is still an agency goal but that

postponement was necessary for two reasons: recent legislative

requirements that prohibited the use of federal-aid highway funds for this

activity and negative comments received on FHWA’s August 31, 1993,

Federal Register notice that requested comments on sign conversion. The

comments emphasized the high cost of converting highway signs and

raised concerns about how conversion would be financed. Since sign

conversion is still a goal, FHWA is continuing with activities to support

conversion, such as converting its manual on highway signs into dual

units—English and metric.

No comprehensive national estimate of the costs to convert U.S. highway

signs to metric units has been developed, and most states have not

developed anything beyond very preliminary estimates. One exception,

Alabama, developed an average conversion cost of about $70 per sign in

February 1995. If Alabama’s estimate is accurate, the cost of converting

the approximately 6 million signs on the nation’s state and local roads

Page 1 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

could amount to about $420 million.1 This estimate is very soft, however,

because, among other things, FHWA’s estimate of the number of signs is a

“guesstimate.” FHWA has tasked its contractor—Battelle—with developing

a more comprehensive, data-driven estimate for various conversion

options by January 1996 so that FHWA will have a basis to choose which

option to implement. However, there is concern that little data may be

available to estimate sign conversions on local roads because inventories

of local signs may not exist. Moreover, Battelle will not be including the

costs for educating the public about the metric system before the highway

signs are converted, which is critical to a safe conversion.

Background 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, 1991.2

1

FHWA was not able to break down the 6 million signs in terms of highway signs and milepost

markers. Therefore, our estimate of $420 million does not factor in Alabama’s estimate of $90 each to

replace milepost markers with kilometer posts.

2

Metric Conversion: Future Progress Depends Upon Private Sector and Public Support

(GAO/RCED-94-23, Jan. 13, 1994). This report provides information on federal agencies’

implementation of metric conversion.

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B-260979 

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.3

 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.4

FHWA’s Metric Conversion

Plan

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.5

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

3

DOT’s metric planning guidelines states that where exclusions are claimed, they should be based on

quantitative information and contain suitable analytical procedures for determining their practicality

or significant inefficiencies. However, there was no further definition of practicality or inefficiency.

4

In a memo to the Department of Commerce, the Secretary of Transportation noted that FAA programs

relating to air traffic control, aircraft certification, and air safety regulations represent exceptions to

DOT’s plans for conversion to the metric system because by international agreements these systems

use nonmetric measures.

5

FHWA has issued guidance on the granting of exceptions to metric conversion for construction

contracts advertised for bids after September 30, 1996. Basically, state exceptions will be granted only

to states that have demonstrated a conscientious effort to convert and are committed to the full use of

the metric system. State exceptions will be granted on a project-by-project basis.

Page 3 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

construction and maintenance. According to FHWA, most state DOTs will

meet FHWA’s target dates for most elements of metric conversion.

Table 1: FHWA’s Metric Transition

Timetable Program elements/activities Target date Status

Develop FHWA’s metric conversion plan Approved 10-31-91

Initiate revision of pertinent laws and

regulations that serve as barriers to metric

conversion

Ongoing

Conversion of FHWA’s manuals, documents,

and publications

1994 Ongoing

Convert FHWA’s data collection and reporting 1995 Ongoing

Newly authorized Federal Lands Highway and

Federal-aid construction contracts in metric

units only

9-30-96 Ongoing

Standards for highway signs 9-30-96 Postponed until

sometime after 1996

Source: FHWA.

Highway Sign

Conversion

Requirement Deferred

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.6

 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

6

The NHS, as established in the Intermodal Surface Transportation Efficiency Act of 1991, is to include

a network of federal-aid roads of national significance totaling approximately 155,000 miles. The

Congress must approve the final NHS network by September 30, 1995.

Page 4 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

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.7

 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.

Conversion Options Exist FHWA detailed three options for converting highway signs in an August 31,

1993, Federal Register notice to obtain public comment.

7

FHWA requires that certain reports and reporting processes be in metric units beginning with fiscal

year 1995. The data and information needed to meet the reporting processes are often obtained from

field surveys, inventories, and permits. The customary milepost is used to document and locate much

of this work. According to FHWA officials, states would gather the data in English units and

mathematically convert the data to metric units.

Page 5 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

• 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.

Page 6 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

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.8

 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.

Moreover, unlike FHWA’s option 1, this approach would also allow for the

signs to be changed to metric concurrently over the same short period as

overlays are removed or metric unit overlays are added for those

English-unit signs that had not been replaced during maintenance.

One open question concerning Alabama’s approach is whether the state

will remove the overlays and convert to metric if FHWA decides not to

require conversion. From a safety standpoint, it may not be prudent for

one state to convert and the surrounding states to keep their signs in

English units. FHWA officials said that they had not decided on a course of

action if conversion were not mandatory and some states converted and

others did not.

The Cost of Highway

Sign Conversion

Could Be Substantial

FHWA has not estimated the nationwide costs of highway sign conversions.

However, on the basis of Canada’s experience in metric sign conversion as

well as the work done to date by Alabama, “ballpark” estimates of about

$334 million and $420 million can be calculated. In 1977, the Canadian

Ministries changed about 241,000 signs (using overlays) on 300,000 miles

of highway, which is about the number of highway miles in California and

Texas. The conversion took 2 months and cost about $13.4 million in 1995

U.S. dollars, or $55.70 per sign ($6.1 million or $25.43 per sign in 1977

Canadian dollars). The number of Canadian signs is a fraction of FHWA’s

estimate that about 6 million signs on the nation’s state and local roads

would need to be changed. Using Canada’s cost data, the United States

conversion could cost about $334 million. However, this estimate could

vary depending on the length of implementation and the replacement

method chosen.

In 1993, AASHTO issued its “Guide to Metric Conversion.” The guide

included a case study on Alabama that used information on the number

and types of signs from one area of the state to develop conversion cost

8

Because Alabama’s metric signs will have overlays in English units, the driving public will not be

using metric speed limits, distances, or other measurements.

Page 7 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

estimates.9 Initially, Alabama estimated that it would cost $2.7 million to

convert its state highway signs, using the quick-conversion option, to

metric units by October 1995. After the initial estimate, Alabama increased

its estimate to $3.8 million (at about $70 per sign), to include an additional

$1.1 million to install kilometer markers for data collection purposes.10

Assuming that nationwide conversion costs would be similar to Alabama’s,

changing the nation’s 6 million highway signs on state and local roads

could cost about $420 million. We termed this a ballpark estimate because

there are a number of factors that could affect the estimate. For example,

the validity of FHWA’s estimate of 6 million signs, as well as the mix of

signs—large ones, small ones, or milepost markers—could be important in

determining costs.

Eight of the nine states that we contacted provided very preliminary cost

estimates, ranging from a low of $1 million to a high of $20 million, for

changing their highway signs on state roads.11 The difference in estimates

depends on the method and number of signs for conversion. Because FHWA

postponed the conversion, FHWA officials told us that most states have not

developed cost estimates. Many states do not have information on the

number of signs that they would need to change on local roads or the

costs involved. Several state officials noted in the 1993 Federal Register

notice that since there are many more miles on local roads than state

roads, the sign conversion costs could be quite substantial. According to

an FHWA official, about 70 percent (or 2.7 million) of the nation’s 3.9 million

miles of public roads are classified as local roads.

In January 1995, FHWA hired a contractor—Battelle—to develop national

cost estimates for each of the three conversion options (and variations of

those options) spelled out in the August 31, 1993, notice. To develop

national cost estimates, Battelle plans to use information from state and

local jurisdictions that have computerized sign inventories. According to

an FHWA official, obtaining information at the local level may be difficult

because local road sign inventories may not be maintained. If local

inventories are not available, Battelle may have to rely on other

methodologies, such as statistical sampling techniques, to provide a basis

9

Alabama’s DOT used information collected from one region of the state on the number and types of

signs that need to be converted and extrapolated the numbers for the entire state. The state DOT’s

field inventory found that 1 out of every 12 signs would need to be changed into metric units on state

roads, at an average cost of $70 per sign. Some signs, such as warning, parking, and regulatory signs,

would not have to be changed.

10This estimate does not include the cost of converting highway signs on local roads.

11The states that we contacted were Alabama, Colorado, Florida, Georgia, Illinois, Indiana, North

Carolina, Tennessee, and Virginia. According to FHWA, these states were the furthest along with

metric signage. One state—Georgia—had not formulated any estimate for sign conversion.

Page 8 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

for estimating costs of changing local road signs to metric. The study is

just getting started and is scheduled for completion in January 1996.

Metric Education Is

Important But Costs Are

Unknown

State and local officials, AASHTO, and an American Trucking Association

official all said that an important component to highway sign conversion is

public education. Without a more comprehensive national conversion

effort that would seek to educate all parts of our society on the metric

system, FHWA and state DOTs might have to establish and fund an education

program before signs are converted.

According to AASHTO’s 1993 “Guide to Metric Conversion,” careful

planning and a public information campaign are largely credited for

Canada’s smooth transition to metric units. The public had been prepared

for the conversion through displays of the new signs, full-page newspaper

advertisements, radio and TV spots, and informational pamphlets.

Moreover, since highway sign conversion was just one part of Canada’s

overall effort to convert the country to the metric system, the program

began with several years of close cooperation and careful planning among

government agencies.

AASHTO’s 1993 guide also states that while public information programs

are essential to conversion, a large part of educating the public can be

handled better by means other than those at the immediate disposal of the

highway agency. The guide points out that the Secretary of Commerce has

been given the lead to establish a metric education program, and AASHTO

believes that the Subcommittee on Public Education and Awareness,

established by the Secretary of Commerce, is a “very appropriate

mechanism for conducting a national awareness campaign.”

However, our January 1994 report on federal metric conversion activities

raises questions about the limited actions that have been taken at the

federal level to foster metric education. Furthermore, the report points out

that the federal government by itself cannot achieve the goal of metric

conversion. The government must depend upon support from its private

sector suppliers and from the public; therefore, a national dialogue is

critical to defining the next steps in decision-making about a national

metric conversion effort.

If the federal government, under the leadership of the Department of

Commerce, does not actively lead a nationwide conversion education

effort, FHWA and state DOTs would be taking the lead in educating the

Page 9 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

public on the metric system. While FHWA is planning for public awareness

and education as part of the sign conversion process, being the lead

agency for public awareness out of necessity, rather than being part of an

overall national conversion education effort, is a very different matter.

However, unless FHWA and the state DOTs take the lead, it will be difficult

for the driving public to become educated or, at a minimum, aware of the

differences between metric and English highway signs. However, FHWA has

not required Battelle to determine the cost of educating the driving public

under each option.

Conclusions The Congress designated the metric system as the preferred measurement

system in 1988; however, it passed appropriations legislation in 1994 and

1995 that prohibited federal funding of converting highway signs to metric

units. As a result, FHWA has postponed requiring states to implement the

conversion. The majority of comments on FHWA’s conversion options

opposed conversion because of the costs. While implementation is on

hold, FHWA has an opportunity to revisit the safety and cost implications of

highway sign conversion to metric units. Battelle’s cost study could

provide the information needed for such an assessment.

Canada’s experience and Alabama’s estimate provide the basis for

developing ballpark national estimates to convert highway signs on state

and local roads of $334 million and $420 million, respectively. FHWA has

tasked Battelle with developing a more comprehensive, data-driven

estimate for various conversion options. However, there is concern that

little data may be available to estimate the cost of converting signs on

local roads. Moreover, it is unclear who is responsible for metric

education and how it will be paid for.

Recommendations To help to ensure that the Federal Highway Administration has sufficient

information to analyze the implications of the metric conversion of

highway signs, we recommend that the Secretary of Transportation direct

the Administrator, Federal Highway Administration, to expand the

national cost estimate study to include the potential costs of educating the

public about converting highway signs to metric units.

Agency Comments We met with the Chiefs of the Contract Administration and Technical

Development Branches, FHWA, and the Assistant for Energy Policy from the

Office of the Secretary to obtain their views on a draft of this report. FHWA

Page 10 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

disagreed with our proposed recommendation that it expand Battelle’s

cost estimate study to include potential education costs for sign

conversion. FHWA said that it intends to play a role in metric education and

that the states could use the material that it develops or build on those

materials with an educational plan of their own. Since it is uncertain how

education will be handled or how much it will cost nationwide, we

continue to believe that developing such an estimate will help to ensure

that the cost estimates developed by Battelle will include all potential

costs of conversion.

Scope and

Methodology

To evaluate the status and costs of converting the nation’s highway signs

to metric units, we interviewed responsible officials from FHWA, Ontario’s

Ministry of Transportation, the Transportation Association of Canada, the

Transportation Research Board, and AASHTO. We also discussed highway

sign conversion and its cost with officials from nine state highway

departments—Alabama, Colorado, Florida, Georgia, Illinois, Indiana,

North Carolina, Tennessee, and Virginia. These states were identified by

FHWA as being the furthest along with metric signage and could provide a

range of cost estimates for converting highway signs to metric units.

We also reviewed the laws and regulations pertinent to metric signage,

such as the Metric Conversion Act, as amended; FHWA’s Metric Conversion

plan; Federal Register notices; and DOT’s appropriations bills for fiscal

years 1994 and 1995. We conducted our review between October 1994 and

April 1995 in accordance with generally accepted government auditing

standards.

As agreed with your office, unless you publicly announce its contents

earlier, we plan no further distribution of this report until 7 days after the

date of this letter. At that time, we will send copies to interested

congressional committees; the Secretary of Transportation; the

Administrator, Federal Highway Administration; and the Director, Office

of Management and Budget. We will also make copies available to others

upon request.

Page 11 GAO/RCED-95-156 Metric Sign Conversion
B-260979 

If you have any questions concerning this report, I can be reached at

(202) 512-2834. Major contributors to this report are listed in appendix I.

Sincerely yours,

Kenneth M. Mead

Director, Transportation Issues

Page 12 GAO/RCED-95-156 Metric Sign Conversion
Page 13 GAO/RCED-95-156 Metric Sign Conversion
Appendix I 

Major Contributors to This Report

Resources,

Community, and

Economic

Development

Division, Washington,

D.C.

Gary L. Jones

Susan A. Fleming

Katherine Chenault

(342903) Page 14 GAO/RCED-95-156 Metric Sign Conversion
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