Transportation safety is a highly contentious issue in the design of cities and communities. To enhance community livability, urban designers, architects and city planners often encourage the placement of street trees, aesthetic street lights, and other roadside features in a buffer zone between the pedestrian realm and the vehicle travelway. While such designs clearly enhance the aesthetic quality of a roadway, conventional geometric design practice regards roadside features located in the clear zone as fixed-object hazards, and strongly discourages their use. This study examines roadside safety in urban environments to better understand the nature of urban fixed-object crashes, as well as the safety impacts of livable streetscape treatments. While the prevailing assumption is that livable street treatments have a negative impact on a roadways safety performance, the existing empirical evidence indicates that such designs are much safer than more conventional roadside designs. Current safety objections to the use of livable street treatments are not based on empirical evidence, but are instead the result of a design philosophy that systematically overlooks the real-world operating behavior of road users. This study details the origin and evolution of this philosophy, termed passive safety, and subjects it to an empirical test to evaluate its applicability to urban arterial roadways. It finds that passive safety assumptions do not meaningfully explain empirical observations of crash frequency and severity. To enhance contemporary geometric design practice, this study then proceeds to more thoroughly examine the nature and characteristics of urban roadside crashes, and proposes a new design approach, termed positive design that better addresses the twin goals of safety and livability.

Scenic corridor protection can be viewed as a microcosm of all land use and protection concerns. The issue has been a topic of discussion among a select few land use professionals, including landscape architects, highway engineers and land use lawyers, for over fifty years. However, the acceleration of land development into previously undisturbed scenic areas, coupled with recent federal initiatives aimed at the inclusion of scenic byways programs into the 1991 Transportation Bill, has increased discussions on scenic byway issues, including questions on the success or failures of scenic corridor protection. To date, there has been little research on the issues and concerns of scenic corridor management and protection, especially at the state level. This thesis is an attempt to gauge the status of scenic corridor protection among those states with several years experience in the field and to offer other states some insights as to tools, issues and concerns involved with corridor management and protection. The process was achieved through a combination of telephone interviews, a questionnaire and case studies of each participant state. Indications are that the field is currently fragmented in terms of tools and methods of management and many managers feel a sense of frustration at the lack of a holistic approach to scenic corridor protection. / Master of Landscape Architecture