In 1992, the Congress directed the Secretary of Transportation to revise the Manual on Unifrom Traffic Control Decives to include a standard for minimum levels of retroreflectivity that must be maintained for traffic signs. The FHWA already had an active research program investigating the nighttime visibility of traffic signs, and responded to the congressional mandate by publishing a set of recommendations for minimum maintained sign retroreflectivity levels in October 1993. An analysis of the impacts of the proposed minimum maintained traffic sign retroreflectivity levels was published in April 1998.
The following document updates the 1998 report on the national impact of minimum maintained traffic sign retroreflectivity levels, and addresses concerns expressed in four FHWA-sponsored workshops that were held in 2002. The primary sources of information for this effort are previous studies related to the benefits of improved signage and the impacts of implementing sign system upgrades.
This report will be of interest to State and local agencies with responsibility for traffic signs and people involved in traffic sign maintenance.
FHWA-HRT-07-042 2. Government Accession No. 3. Recipient's Catalog No.
Carl K. Andersen 8. Performing Organization Report No.
This report analyzes the impacts that might be expected from the adoption of proposed minimum maintained retroreflectivity levels for traffic signs to improve night visibility. The report evaluates the broad spectrum of concerns expressed by State and local agency staff at four workshops held during the summer of 2002. These include administrative, fiscal, implementation, and tort liability concerns.
The report includes a summary of previous studies, including those of several State agencies, to determine the impacts of the proposed new minimum maintained levels for traffic sign retroreflectivity. The various sign cost elements are identified and changes attributable to the new minimum levels of retroreflectivity are isolated. The cost of sign face materials is seen as the major source of increased costs. The cost impact is determined to be a function of the condition of existing signs, State and local agency practices on the use of sign materials, and current procedures for sign management.
The report provides estimates of the National impact of the proposed minimum levels generated by the models previously developed using updated inputs for sign material costs and road mileage. It was assumed that the distribution of non-compliant signs has remained the same. Estimates of the costs for upgrading street name and overhead guide signs were also generated to cover the full spectrum of signs covered by the proposed minimum levels. National sign replacement costs incurred as a result of proposed minimum maintained retroreflectivity levels are estimated to be $37.5 million. Using a 7-year implementation period for regulatory, warning, and guide signs and a 10-year implementation period for street name and overhead guide signs, the annual impacts are estimated to be $4.5 million for years 1 through 7 and $2.1 million for years 8 through 10. The estimates are based upon the added cost of higher performance sign materials, with the majority of sign replacements conducted as part of normal sign maintenance cycles. The labor, equipment, and mileage costs for sign replacement were excluded under the assumption that the proposed implementation period was long enough to allow replacement of non-compliant signs under reasonable maintenance cycles.
The report concludes that there will be increases in the costs to agencies resulting from the need to use more expensive sign face materials to increase retroreflective performance, but there should be no impacts on the costs of other sign elements. Agencies may experience a reduction in service life costs because of the longer service life of the improved sign face materials.