Objective: The aims of this study were to extend the current literature on school climate that is focused on understanding how teacher, administrator, and student perceptions about driving-focused aspects of the social, educational, and institutional climate of schools can affect students’ achievement, behavior, and adjustment toward the development of the concept of a school safe driving climate (SSDC) and initiate the development of tools and processes for assessing SSDC. Methods: A mixed methods approach was used to develop an initial version of a survey-based measure of SSDC that involved self-report surveys (students) and in-depth interviews (teachers). Exploratory factor analytic procedures identified SSDC constructs and a regression framework was used to examine associations among SSDC constructs and self-reported driving behaviors. Qualitative data were subjected to inductive analysis, with a goal of elucidating teachers’ perspectives on SSDC and an SSDC intervention. Results: The study sample consisted of 947 adolescents (48% male) from one large high school and 44 teacher advisors. Participants were recruited from a school participating in a state-wide effort to promote transportation safety through peer-led programming. Two SSDC factors were identified—Administrative contributions to school safety and value of school safety—that were associated with adolescents’ perceptions of their driving behaviors. Adolescents perceived that the intervention affected administrative safety. Teacher interviews contextualized these results and provided guidance on program revisions. Conclusions: Safe driving climate may be an important, modifiable, and measurable aspect of school climate. Additional research is needed to refine the assessment tool and to use it in longitudinal and experimental studies.