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                Association of Median Width and Highway Accident Rates
Publication Information
              Publication External Link:Link not available
              Publication Type:Article
                      Abstract:Data for two states have been extracted from the Highway Safety Information System and used to examine the effect of median width on the frequency and severity of accidents. Log-linear models for accident rates have been used to describe the effect of median width after adjusting for other variables. Effects have been estimated by the quasi-likelihood technique assuming a negative binomial variance for the accident count per roadway section. Results for both states indicate that total accident rates and rates for specific types and severity decline rapidly when median width exceeds about 25 ft (7.6 m). Policy guidelines for median widths are somewhat nebulous, partly due to the lack of large well conducted studies providing quantitative information on this topic. The results provide a basis for the development of more precise guidelines regarding median width.
              Publishing Date:October 1993
                                                  FHWA Program(s):Research
              Safety
              AMRP Program(s):Safety Data and Analysis
              FHWA Activities:Highway Safety Information System
              Subject Area:Safety and Human Factors U.S. DEPARTMENT OF TRANSPORTATION

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