Agenda - Council - 07/22/2008 - Laserfiche WebLink

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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 FH«~A more than a decade later. The original analysis tried to improve upon previous research by limiting variables; such as road`~~ay geometric design and roadway access controls. The FH~~JA 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 «~as performed to ,determine the expected crash rates. An azlalysis of variance of the regression coefficients found that the number of billboards on a section «~as statistically significant, The reanalysis found a strong correlation bett~~een the number of billboards and crash rates as sho«~n in Table 1. Table 1. FH7~JA Reanalysis of Faust~nan's Fii~.dil~.gs. Expected No. of Cumulative Increase No. of Billboards Accidents in a ~ Accident Rate 5-year Period 0 5.92 1 6.65 12.3 2 7.3 8 2~:2 8 11 37.0 4 8.84 49.3 5 9.57 61.7 Federal Highway Administration Safety and Environmenfai Design Gonsiderafions in the Use of Commercial Electronic !/ariable-Message Signage (Wachtel & Netherton, 1980) 6 This extensive revie«~ 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 disallo«~ing billboards because of the "readily understood logic that a driver caru~ot 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 la«~ 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 bet«~een crashes and roadside features. ~$ -216-