Agenda - Council - 11/13/2012 - Laserfiche WebLink

Home

Faustman (California Route 40) Field Study (1961)4 and Federal Highway Administration, Reanalysis of Faustman Field Study (1973)5 Two studies that appear to have stood the test of time are Faustman's original analysis of California Route 40 and its re-examination by FHWA more than a decade later. The original analysis tried to improve upon previous research by limiting variables, such as roadway geometric design and roadway access controls. The FHWA reanalysis focused on disaggregating the data and converting actual crashes to expected crash rates on specific roadway sections. Each of the sections was given a value based on the number of billboards on the section. A linear regression was performed to determine the expected crash rates. An analysis of variance of the regression coefficients found that the number of billboards on a section was statistically significant. The reanalysis found a strong correlation between the number of billboards and crash rates as shown in Table 1. Table 1. FHWA Reanalysis of Faustman's Findings. Expected No. of No. of Billboards Accidents in a 5-year Period 0 5.92 1 6.65 2 7.38 3 8.11 4 8.84 5 9.57 Cumulative Increase in Accident Rate 12.3 24.2 37.0 49.3 61.7 Federal Highway Administration Safety and Environmental Design Considerations in the Use of Commercial Electronic Variable -Message Signage (Wachtel & Netherton, 1980) 6 This extensive review provides a comprehensive discussion of roadside advertising research as of 1980. The study authors noted "attempts to quantify the impact of roadside advertising on traffic safety have not yielded conclusive results." The authors found that courts typically rule on the side of disallowing billboards because of the "readily understood logic that a driver cannot be expected to give full attention to his driving tasks when he is reading a billboard." Because the distraction evidence is not conclusive, these decisions were generally not based on empirical evidence. The research review noted that accident reports often cite "driver distraction" as a default category used by uncertain law enforcement officers who must identify the cause of a crash. As a result, the authors believe crashes due to driver distraction are not always properly identified. In addition, law enforcement officers often fail to indicate the precise crash locations on crash reports, making it difficult to establish relationships between crashes and roadside features. 5