TWO-WAY LEFT-TURN LANE WITH A RAISED MEDIAN: ATLANTA'S MEMORIAL DRIVE

In 1990, the Georgia Department of Transportation replaced a two-way left-turn lane (TWLTL) with a raised median separation along 4.34 miles of Memorial Drive in greater Atlanta. In the year after completion, the project prevented about 300 crashes and 150 injuries. There was a 37% reduction in total accident rate and a 48% drop in the injury rate. Left-turn accidents between intersections were virtually eliminated. However, after the project, traffic volumes dropped 12% within the project and only 5.5% outside it (1991 was a recession locally and nationwide). Articles appeared in the local newspapers quoting merchants as saying that the median project has hurt business by eliminating left-turns into and out from their establishments. The project did not include any measures to improve inter-parcel access by providing frontage roads or rear alleyways or joint parking lots. The authors concluded that the project probably did have a negative effect on stores at mid-block locations and those that must do a large-volume business because of a small profit on each sale. These results were presented and published at the First National Access Management Conference, in 1993. It was reported there that, as of May of 1993, after over 2.5 years of the median, not a single fatality had occurred, whereas in the 11.6 years preceding the project there were 15 fatalities, including six pedestrian deaths. The present paper updates the Memorial Drive experience, reporting the longer-term impacts on both safety and abutting-business activity after eight years of the raised median. As of the date of this presentation in early October, 1998, there still has not occurred the first fatality, either motorist or pedestrian. However, the enormous percentage reductions in crashes experienced during the first year have not been found to hold up over time, at least on a project-wide basis. The annual number of crashes has been increasing since 1992, despite the fact that traffic volumes are gradually decreasing. However, the paper suggests that this increase is not significantly different from the county-wide increase during the same period and therefore is not attributable to the median. Interviews with the traffic police in the area revealed strong opinions that driver inattention is to blame for the upward trend in crash frequency. There is a perception that in earlier times, before the invention of the cell phone, drivers were much less distracted from the task at hand and more likely to take their driving seriously. Memorial Drive, once prosperous with leading retail stores and automobile dealers, now has retail-vacancy rates of 15%, twice the Atlanta average. Newspaper accounts of the decline cite the raised median as one factor of several, but the paper shows that, in fact, the demographics of the corridor were weakening years before the median was built, due to socioeconomic influences such as court-ordered desegregation and the construction of a rapid-rail system.